6th Grade Math Quiz: Find Surface Area Using Nets

20 questions · exam conditions

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Find Surface Area Using NetsQuestion 1 of 20

A rectangular prism has a length of 9 inches, width of 4 inches, and height of 6 inches. Sarah draws a net for this prism but accidentally makes one dimension 1 inch longer than it should be on every face that includes that dimension. If the incorrect dimension is the width, what is the surface area of Sarah's incorrect net?

258 square inches because the width becomes 5 inches on all relevant faces

228 square inches because only some faces are affected by the error

288 square inches because the error adds extra area throughout the net

248 square inches because the mistake partially cancels out across opposite faces

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6th Grade Math Quiz

6th Grade Math Quiz: Find Surface Area Using Nets

Practice Find Surface Area Using Nets in 6th Grade Math with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Find Surface Area Using Nets, giving you a quick way to practice the rules, question types, and explanations that matter most for 6th Grade Math.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

258 square inches because the width becomes 5 inches on all relevant faces (correct answer)
228 square inches because only some faces are affected by the error
288 square inches because the error adds extra area throughout the net
248 square inches because the mistake partially cancels out across opposite faces

Explanation: The correct prism has dimensions 9×4×6, giving surface area 2(9×4) + 2(9×6) + 2(4×6) = 72 + 108 + 48 = 228 sq in. Sarah makes the width 5 instead of 4. Her net has: 2(9×5) + 2(9×6) + 2(5×6) = 90 + 108 + 60 = 258 sq in. The width appears in 4 of the 6 faces (two 9×4 faces become 9×5, and two 4×6 faces become 5×6). Only the 9×6 faces remain unchanged.

Question 2

Tyler is building a triangular prism for a school project. The triangular bases are right triangles with legs of 5 cm and 12 cm. The prism has a height of 8 cm. If Tyler wants to cover the entire prism with decorative paper, how much paper does he need?

330 square centimeters to account for overlapping and waste during application
300 square centimeters representing the total surface area of all faces (correct answer)
270 square centimeters after subtracting areas where faces connect together
240 square centimeters covering only the three rectangular side faces

Explanation: The triangular prism has 5 faces: 2 triangular bases and 3 rectangular sides. Triangular bases: area = (1/2)(5)(12) = 30 sq cm each, so 2 × 30 = 60 sq cm total. For the rectangular sides, we need the lengths of all three sides of the triangle. The hypotenuse is √(5² + 12²) = √(25 + 144) = √169 = 13 cm. The three rectangular faces have areas: 5 × 8 = 40 sq cm, 12 × 8 = 96 sq cm, and 13 × 8 = 104 sq cm. Total surface area: 60 + 40 + 96 + 104 = 300 sq cm.

Question 3

A small storage box is a rectangular prism with dimensions $3\text{ cm} \times 4\text{ cm} \times 5\text{ cm}$ . A net for the box would have 6 rectangles: two $3\times4$ , two $3\times5$ , and two $4\times5$ . What is the total surface area of the box?

$47\text{ cm}^2$
$90\text{ cm}^2$
$60\text{ cm}^2$
$94\text{ cm}^2$ (correct answer)

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, and surface area is the sum of all face areas; for a 3×4×5 cm prism, faces are 3×4=12 cm² (front/back, twice), 3×5=15 cm² (top/bottom, twice), 4×5=20 cm² (sides, twice), total 2(12+15+20)=94 cm², using A=lw for rectangles. For example, the net shows six rectangles (two 3×4, two 3×5, two 4×5), calculate 2×12 + 2×15 + 2×20 = 24 + 30 + 40 = 94 cm². The correct net includes all six faces, and the surface area is 94 cm². A common error is missing the pairs and adding only one of each, like 12+15+20=47 cm², or arithmetic mistakes leading to 90 or 60 cm², or using cm³ instead of cm². To create a net, identify the six rectangles in three equal pairs, arrange them connected flat, and label dimensions. To calculate, find each face type's area with A=lw, count two of each, sum all areas for 94 cm² in square units; in real life, this determines wrapping paper needed for the box.

Question 4

A cube has edge length $4\text{ in}$ . If you unfold it into a net, you get 6 congruent squares. What is the surface area of the cube?

$96\text{ in}^2$ (correct answer)
$80\text{ in}^2$
$64\text{ in}^2$
$16\text{ in}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a cube unfolds to 6 squares, and surface area is the sum of all face areas; for an edge of 4 in, each square is 4×4=16 in², total 6×16=96 in², using A=lw for squares. For example, the net shows six congruent 4×4 squares, calculate 6×16=96 in². The correct net includes all six faces, and the surface area is 96 in². A common error is calculating only four faces like 4×16=64 in², or one face 16 in², or misadding to 80 in², or using in³ instead of in². To create a net, identify the six equal squares, arrange them connected flat without overlap, and label dimensions. To calculate, find the area of one square with A=lw, multiply by six for 96 in² in square units; in real life, this tells the material needed to cover a cube-shaped die or box.

Question 5

A storage box is shaped like a rectangular prism with dimensions $3\text{ cm} \times 4\text{ cm} \times 5\text{ cm}$ . Which net could be folded to make this box and what is the total surface area of the box?

(Each rectangle in the net should match one face of the prism.)

Net: 6 rectangles (two $3\times4$ , two $3\times5$ , two $4\times5$ ); Surface area $=94\text{ cm}^2$ (correct answer)
Net: 5 rectangles (two $3\times4$ , one $3\times5$ , two $4\times5$ ); Surface area $=74\text{ cm}^2$
Net: 6 rectangles (two $3\times4$ , two $3\times5$ , two $4\times5$ ); Surface area $=47\text{ cm}^2$
Net: 6 rectangles (two $3\times4$ , two $3\times4$ , two $4\times5$ ); Surface area $=88\text{ cm}^2$

Explanation: Nets are used to represent 3D figures in 2D by unfolding them to show all faces, and we use them to calculate surface area by summing the areas of all the 2D shapes in the net. A net is the unfolded flat pattern of a 3D figure showing all its faces as 2D shapes; for example, a rectangular prism unfolds to 6 rectangles, and a triangular prism to 2 triangles and 3 rectangles. Surface area is the sum of the areas of all faces; for a rectangular prism with dimensions l,w,h, it's 2(lw + lh + wh). For example, for a rectangular prism 3×4×5, the net shows 6 rectangles (two 3×4=12 each, two 3×5=15 each, two 4×5=20 each), total surface area 2(12+15+20)=94. For this question, the correct net and surface area are Net: 6 rectangles (two 3×4, two 3×5, two 4×5); Surface area =94 cm². Common errors include missing faces, using wrong dimensions like duplicating the wrong pair, arithmetic errors in summing, or halving the total incorrectly. To create a net, identify all 6 faces, draw them connected without overlap, label dimensions; to calculate, find each pair's area, multiply by 2, sum, use cm². Real-world uses include calculating material for boxes; avoid mistakes like counting only 5 faces or wrong units.

Question 6

A rectangular prism has dimensions $6\text{ m} \times 4\text{ m} \times 3\text{ m}$ . A correct net must include two $6\times4$ rectangles, two $6\times3$ rectangles, and two $4\times3$ rectangles. What is the surface area of the prism?

$108\text{ m}^2$ (correct answer)
$72\text{ m}^2$
$84\text{ m}^2$
$132\text{ m}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, and surface area is the sum of all face areas; for a 6×4×3 m prism, faces are 6×4=24 m² (twice), 6×3=18 m² (twice), 4×3=12 m² (twice), total 2(24+18+12)=108 m², using A=lw for rectangles. For example, the net shows two 6×4, two 6×3, two 4×3 rectangles, calculate 2×24 + 2×18 + 2×12 = 48 + 36 + 24 = 108 m². The correct net and surface area are as described, totaling 108 m². A common error is missing pairs like 24+18+12=54 m² then doubling wrongly to 72 or 84 m², or adding extra to 132 m². To create a net, identify the six rectangles in three equal pairs, arrange connected flat, and label dimensions. To calculate, find each face type's area with A=lw, count two of each, sum for 108 m² in square units; in real life, this could determine paint needed for a room-sized prism model.

Question 7

A student is checking a net for a rectangular prism with dimensions $5\text{ m} \times 3\text{ m} \times 2\text{ m}$ . The student computed $5\cdot3 + 5\cdot2 + 3\cdot2 = 31$ and said the surface area is $31\text{ m}^2$ .

Which statement is correct?

The student is correct because surface area is $lw+lh+wh$ .
The student forgot to multiply by 2 for the pairs of opposite faces; the surface area is $62\text{ m}^2$ . (correct answer)
The student should have found volume instead; the surface area is $30\text{ m}^2$ .
The student double-counted faces; the surface area is $15\text{ m}^2$ .

Explanation: Nets are used to represent 3D figures in 2D by unfolding them to show all faces, and we use them to calculate surface area by summing the areas of all the 2D shapes in the net. A net is the unfolded flat pattern of a 3D figure showing all its faces as 2D shapes; for example, a rectangular prism unfolds to 6 rectangles, and a triangular prism to 2 triangles and 3 rectangles. Surface area is the sum of the areas of all faces; for a rectangular prism with dimensions l,w,h, it's 2(lw + lh + wh). For example, for dimensions 5×3×2, faces 5×3=15, 5×2=10, 3×2=6, total 2(15+10+6)=62. For this question, the correct statement is the student forgot to multiply by 2 for the pairs of opposite faces; the surface area is 62 m². Common errors include confusing with volume, double-counting, or halving instead. To create a net, identify pairs, draw, label; to calculate, add unique then ×2, use m². Real-world uses include building materials; avoid mistakes like single faces or wrong formula.

Question 8

A rectangular prism measures $6\text{ ft} \times 5\text{ ft} \times 4\text{ ft}$ . A net would include two $6\times5$ rectangles, two $6\times4$ rectangles, and two $5\times4$ rectangles. What is the surface area?

$120\text{ ft}^2$
$148\text{ ft}^2$ (correct answer)
$74\text{ ft}^2$
$100\text{ ft}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D patterns showing all faces, and using nets to calculate surface area by summing rectangle face areas. A net for a rectangular prism unfolds to 6 rectangles, and the surface area is the sum of all; for example, a 6 ft × 5 ft × 4 ft prism has faces 6×5=30 ft² (twice), 6×4=24 ft² (twice), 5×4=20 ft² (twice), totaling 2(30+24+20)=148 ft² using A=lw. For instance, the net shows two 6×5 (60 ft²), two 6×4 (48 ft²), two 5×4 (40 ft²), summing to 148 ft². The correct surface area is 148 ft², matching the areas of the six rectangles in the net. A common error is halving instead of doubling, like (30+24+20)=74 ft², or wrong dimensions like using 6×6=36 instead of 6×5. To create a net, identify the six rectangles in pairs, arrange unfolded connected, and label each with lengths. To calculate, compute each type's area, multiply by two, sum with ft² units, applicable to painting a box's surface.

Question 9

A student claims the surface area of a rectangular prism with dimensions $3\text{ cm} \times 4\text{ cm} \times 5\text{ cm}$ is $47\text{ cm}^2$ because $3\cdot4 + 3\cdot5 + 4\cdot5 = 47$ . Is the student correct? Choose the best answer.

Yes, because $47\text{ cm}^2$ is the area of the largest face.
No, because you should multiply $3\cdot4\cdot5$ to get $60\text{ cm}^2$ .
Yes, because you add the areas of the three different faces once.
No, because a net has 6 faces, so you must double $47$ to get $94\text{ cm}^2$ . (correct answer)

Explanation: This question tests understanding surface area calculation for a rectangular prism using nets, identifying errors in summing face areas. A net for a 3 cm × 4 cm × 5 cm prism shows 6 rectangles, with correct surface area 2(3×4 + 3×5 + 4×5)=2(12+15+20)=94 cm², but the student only summed one of each pair as 47 cm². For instance, like missing the doubling in examples such as a cube where you multiply by 6, not 1. The student is incorrect because a net has 6 faces, requiring doubling 47 to 94 cm² for opposite pairs. A common error is this exact mistake of not doubling, or confusing with volume as 3×4×5=60 cm³. To calculate correctly, identify all faces, compute areas, double for pairs, sum with cm². This avoids errors in real-world like underestimating wrapping paper.

Question 10

A small aquarium is shaped like a rectangular prism with dimensions $5\text{ in} \times 4\text{ in} \times 3\text{ in}$ . A net for the aquarium (including the top) has 6 rectangles.

What is the total surface area?

$94\text{ in}^2$ (correct answer)
$120\text{ in}^2$
$60\text{ in}^2$
$30\text{ in}^2$

Explanation: Nets are used to represent 3D figures in 2D by unfolding them to show all faces, and we use them to calculate surface area by summing the areas of all the 2D shapes in the net. A net is the unfolded flat pattern of a 3D figure showing all its faces as 2D shapes; for example, a rectangular prism unfolds to 6 rectangles, and a triangular prism to 2 triangles and 3 rectangles. Surface area is the sum of the areas of all faces; for a rectangular prism with dimensions l,w,h, it's 2(lw + lh + wh). For example, for a rectangular prism 5×4×3, net shows two 5×4=20, two 5×3=15, two 4×3=12, total 2(20+15+12)=94. For this question, the correct net and surface area are a net with 6 rectangles; total surface area =94 in². Common errors include not multiplying by 2, confusing with volume, or wrong pairs. To create a net, identify all faces, draw unfolded, label; to calculate, sum paired areas, use in². Real-world uses include aquarium glass; avoid mistakes like single faces or units error.

Question 11

Look at the net diagram. If you fold this net into a three-dimensional shape, which statement about the resulting figure is correct?

The figure will be a rectangular prism with surface area 198 square units
The figure will be a rectangular prism with surface area 186 square units
The figure cannot form a closed rectangular prism due to missing faces (correct answer)
The figure will be a rectangular prism with surface area 174 square units

Explanation: Counting the faces in the net: there are only 5 rectangular faces shown. A complete rectangular prism requires exactly 6 faces (3 pairs of opposite faces). Since this net only has 5 faces, it cannot fold into a closed rectangular prism - there will be one face missing, leaving an opening in the three-dimensional shape. The other choices incorrectly assume the net is complete and attempt to calculate surface area.

Question 12

A triangular prism has a triangular base with base $6\text{ m}$ and height $4\text{ m}$ (so each triangular base has area $\tfrac12\cdot6\cdot4$ ). The prism length is $10\text{ m}$ . The three side rectangles have dimensions $6\times10$ , $4\times10$ , and $5\times10$ (the third side of the triangle is $5\text{ m}$ ). What is the total surface area?

$120\text{ m}^2$
$150\text{ m}^2$
$198\text{ m}^2$
$174\text{ m}^2$ (correct answer)

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D patterns showing all faces, and using nets to calculate surface area by summing rectangle and triangle face areas. A net for a triangular prism unfolds to 2 triangles and 3 rectangles, with surface area as the sum of all; for example, bases with area (1/2)×6×4=12 m² each (24 m² total), and rectangles 6×10=60 m², 4×10=40 m², 5×10=50 m² (150 m² total), summing to 174 m² using A=(1/2)bh for triangles and A=lw for rectangles. For instance, the net shows two triangles (24 m²) and three distinct rectangles (150 m²), totaling 174 m². The correct surface area is 174 m², including both triangular bases and all lateral faces from the net. A common error is forgetting the (1/2) for triangles, using 6×4=24 m² each (48 m²) plus 150 m²=198 m², or missing one rectangle like omitting 50 m² for 124 m². To create a net, identify 2 triangles and 3 rectangles, arrange connected flat with the rectangles between the triangles' sides, and label dimensions. To calculate, find areas with appropriate formulas, count multiples, sum with m² units, useful for real-world like tent material.

Question 13

A science project container is a rectangular prism with dimensions $10\text{ cm} \times 8\text{ cm} \times 5\text{ cm}$ . How much material is needed to cover the outside of the container (surface area)?

$170\text{ cm}^2$
$340\text{ cm}^2$ (correct answer)
$230\text{ cm}^2$
$400\text{ cm}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D patterns showing all faces, and using nets to calculate surface area by summing the areas of rectangle faces for real-world material needs. A net for a rectangular prism unfolds to 6 rectangles, and the surface area is the sum of all face areas; for example, a 10 cm × 8 cm × 5 cm prism has faces of 10×8=80 cm² (twice), 10×5=50 cm² (twice), and 8×5=40 cm² (twice), totaling 2(80+50+40)=340 cm² using A=lw. For instance, the net shows two 10×8 (160 cm² total), two 10×5 (100 cm² total), and two 8×5 (80 cm² total), summing to 340 cm². The correct amount of material needed is 340 cm², covering all six faces as shown in the net. A common error is omitting one pair of faces, like only 2(80+50)=260 cm² plus 40=300 cm², or arithmetic mistakes like 2(80+50+40)=2(170)=340 but misadding to 400. To create a net, identify the six rectangles in three pairs, arrange them unfolded and connected, and label dimensions. To calculate, find each face type's area with A=lw, multiply by two, sum with cm² units, applying to scenarios like covering a container.

Question 14

A rectangular prism has dimensions $6\text{ cm} \times 5\text{ cm} \times 4\text{ cm}$ . How many faces does its net have, and what shapes are they?

8 faces: all rectangles
6 faces: all rectangles (correct answer)
6 faces: 2 squares and 4 rectangles
5 faces: 2 triangles and 3 rectangles

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, as it has six rectangular faces, unlike prisms with triangles or other shapes. For example, for 6×5×4 cm, the net has six rectangles: two 6×5, two 6×4, two 5×4. The net has 6 faces, all rectangles. A common error is thinking it's like a triangular prism with 5 faces (2 triangles, 3 rectangles), or assuming squares if sides equal, or miscounting to 8 faces. To create a net, identify the six rectangular faces in pairs, arrange connected flat, label dimensions. In real life, understanding the net helps in packaging design with exactly six rectangular panels.

Question 15

A cardboard box is shaped like a rectangular prism with dimensions $3\text{ cm} \times 4\text{ cm} \times 5\text{ cm}$ . A net would have 6 rectangles: two $3\times4$ , two $3\times5$ , and two $4\times5$ . What is the total surface area of the box in square centimeters?

$94\text{ cm}^2$ (correct answer)
$47\text{ cm}^2$
$90\text{ cm}^2$
$60\text{ cm}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D patterns showing all faces, and using nets to calculate surface area by summing the areas of rectangle faces. A net for a rectangular prism unfolds to 6 rectangles, and the surface area is the sum of all face areas; for example, a 3 cm × 4 cm × 5 cm prism has faces of 3×4=12 cm² (front and back, counted twice), 3×5=15 cm² (top and bottom, twice), and 4×5=20 cm² (left and right, twice), totaling 2(12+15+20)=94 cm² using the formula for rectangle area A=lw. For instance, the net shows six rectangles: two 3×4 (24 cm² total), two 3×5 (30 cm² total), and two 4×5 (40 cm² total), summing to 94 cm². The correct surface area is 94 cm², as calculated by adding the areas of all six faces from the net. A common error is calculating only one of each pair of faces, like 12+15+20=47 cm², missing that opposite faces are identical and must be doubled. To create a net, identify all six rectangular faces in three pairs of equal opposites, arrange them connected in a flat pattern like a cross, and label each with its dimensions. To calculate surface area, find the area of each face type using A=lw, count two of each, sum them up with squared units like cm², remembering real-world applications like the paper needed to wrap the box.

Question 16

A rectangular prism has dimensions $6\text{ ft} \times 4\text{ ft} \times 3\text{ ft}$ . A student unfolds it into a net and lists the face areas as:

two faces: $6\times4$
two faces: $6\times3$
two faces: $4\times3$

What is the total surface area?

$72\text{ ft}^2$
$24\text{ ft}^2$
$216\text{ ft}^2$
$108\text{ ft}^2$ (correct answer)

Explanation: Nets are used to represent 3D figures in 2D by unfolding them to show all faces, and we use them to calculate surface area by summing the areas of all the 2D shapes in the net. A net is the unfolded flat pattern of a 3D figure showing all its faces as 2D shapes; for example, a rectangular prism unfolds to 6 rectangles, and a triangular prism to 2 triangles and 3 rectangles. Surface area is the sum of the areas of all faces; for a rectangular prism with dimensions l,w,h, it's 2(lw + lh + wh). For example, for a rectangular prism 6×4×3, net shows two 6×4=24, two 6×3=18, two 4×3=12, total 2(24+18+12)=108. For this question, the correct net and surface area are a net with 6 rectangles; total surface area =108 ft². Common errors include not multiplying by 2 for pairs, wrong face areas, or adding incorrectly. To create a net, identify pairs of faces, draw connected, label; to calculate, compute each type and sum, use ft². Real-world uses include painting rooms; avoid mistakes like counting only unique faces or using volume.

Question 17

A gift box is a rectangular prism with dimensions $10\text{ cm} \times 8\text{ cm} \times 5\text{ cm}$ . How much wrapping paper (surface area) is needed to cover all 6 faces of the box (not counting overlap)?

$130\text{ cm}^2$
$400\text{ cm}^2$
$170\text{ cm}^2$
$340\text{ cm}^2$ (correct answer)

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, and surface area is the sum of all face areas; for a 10×8×5 cm prism, faces are 10×8=80 cm² (twice), 10×5=50 cm² (twice), 8×5=40 cm² (twice), total 2(80+50+40)=340 cm², using A=lw for rectangles. For example, calculate 2×80 + 2×50 + 2×40 = 160 + 100 + 80 = 340 cm². The correct surface area for wrapping paper (all faces) is 340 cm². A common error is adding only one of each pair like 80+50+40=170 cm², or miscalculating pairs to 400 or 130 cm². To create a net, identify the six rectangles in three equal pairs, arrange connected flat, and label dimensions. To calculate, find each pair's area with A=lw, multiply by two, sum for 340 cm² in square units; in real life, this determines the paper needed to wrap a gift box without overlap.

Question 18

$340\text{ cm}^2$ (correct answer)
$130\text{ cm}^2$
$400\text{ cm}^2$
$170\text{ cm}^2$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, and surface area is the sum of all face areas; for a 10×8×5 cm prism, faces are 10×8=80 cm² (twice), 10×5=50 cm² (twice), 8×5=40 cm² (twice), total 2(80+50+40)=340 cm², using A=lw for rectangles. For example, calculate 2×80 + 2×50 + 2×40 = 160 + 100 + 80 = 340 cm². The correct surface area for wrapping paper (all faces) is 340 cm². A common error is adding only one of each pair like 80+50+40=170 cm², or miscalculating pairs to 400 or 130 cm². To create a net, identify the six rectangles in three equal pairs, arrange connected flat, and label dimensions. To calculate, find each pair's area with A=lw, multiply by two, sum for 340 cm² in square units; in real life, this determines the paper needed to wrap a gift box without overlap.

Question 19

A rectangular prism has dimensions $5\text{ in} \times 4\text{ in} \times 3\text{ in}$ . A correct net has two $5\times4$ faces, two $5\times3$ faces, and two $4\times3$ faces. Is the surface area $47\text{ in}^2$ ?

Yes, because $5\cdot4+5\cdot3+4\cdot3=47$
No, because $47\text{ in}^2$ counts only 3 faces; the surface area is $94\text{ in}^2$ (correct answer)
Yes, because opposite faces overlap in the net
No, because surface area should be in cubic inches; it is $94\text{ in}^3$

Explanation: This question tests representing 3D figures with nets, which are unfolded 2D representations showing all faces, and using them to calculate surface area by summing the areas of rectangle and triangle faces. A net for a rectangular prism unfolds to 6 rectangles, surface area sums all; for 5×4×3 in, faces 5×4=20 (twice), 5×3=15 (twice), 4×3=12 (twice), total 2(20+15+12)=94 in². For example, adding only one of each like 20+15+12=47 in² counts just three faces, not all six. No, 47 in² is not the surface area because it counts only three faces; the correct is 94 in². A common error is this missing the opposite faces, or thinking nets overlap areas, or using cubic units like 94 in³ instead of in². To create a net, identify all six rectangles, arrange connected without overlap, label dimensions. To calculate, sum all face areas properly for 94 in²; in real life, this avoids underestimating material for a box.

Question 20

A gift box is a rectangular prism with dimensions $10\text{ cm} \times 8\text{ cm} \times 5\text{ cm}$ . You want to cover the entire outside with wrapping paper (no overlap). Using a net of the prism, what total area of paper is needed?

$340\text{ cm}^2$ (correct answer)
$460\text{ cm}^2$
$400\text{ cm}^2$
$170\text{ cm}^2$

Explanation: Nets are used to represent 3D figures in 2D by unfolding them to show all faces, and we use them to calculate surface area by summing the areas of all the 2D shapes in the net. A net is the unfolded flat pattern of a 3D figure showing all its faces as 2D shapes; for example, a rectangular prism unfolds to 6 rectangles, and a triangular prism to 2 triangles and 3 rectangles. Surface area is the sum of the areas of all faces; for a rectangular prism with dimensions l,w,h, it's 2(lw + lh + wh). For example, for a rectangular prism 10×8×5, the net shows 6 rectangles (two 10×8=80, two 10×5=50, two 8×5=40), total surface area 2(80+50+40)=340. For this question, the correct net and surface area are a net with 6 rectangles; total area of paper needed =340 cm². Common errors include not multiplying by 2, adding overlaps, or using volume. To create a net, identify all 6 faces, arrange connected, label dimensions; to calculate, sum areas of all faces, use cm². Real-world uses include wrapping gifts without waste; avoid mistakes like missing pairs or wrong units.