Pre-Algebra - Area of a Rectangle or Square

A rectangle measures inches on its long side, and inches on its short side. What is its area?

square inches

Explanation

To find the area of a rectangle, multiply the length of the long side by the length of the short side. The best answer is:

square inches

Find the area of a rectangle if the perimeter is 10, and the width is 4.

Explanation

Write the perimeter formula for rectangles.

Substitute the perimeter and the width to find the length. The length will be needed to find the area.

Solve for .

Write the formula for the area of a rectangle and solve for the area.

What is the area of a square with a side length of inches?

square inches

Explanation

To find the area of a square, simply multiply the side length by itself. Because the side length of the square in question is , the best answer is:

square inches

Jessica's blanket is 12 square feet. Lisa has a blanket that is half the size of Jessica's blanket. Which of the following are possible dimensions of Lisa's blanket?

$3\ ft\times2\ ft$

$3\ ft\times3\ ft$

$1\ ft\times12\ ft$

$2\ ft\times2\ ft$

Explanation

The area of a rectangle if found by multiplying the length times the width. Here, we know that Lisa's blanket is half the area of Jessica's blanket. Since Jessica's blanket is 12 square feet, that means that Lisa's blanket must be 6 square feet.

The only length and width values that give us 6 square feet when multiplied by one another are 3 feet by 2 feet. This is therefore the correct answer.

Find the area of a rectangle with a width of 4cm and a length that is two times the width.

$32\text{cm}^2$

$32\text{cm}$

$16\text{cm}^2$

$24\text{cm}$

$24\text{cm}^2$

Explanation

The formula for the area of a rectangle is

$A = l \cdot w$

where l is the length of the rectangle, and w is the width.

We know the width of the rectangle is 4cm. The length is two times the width, so the length is 8cm. Now, we substitute. We get

$A = 8\text{cm} \cdot 4\text{cm}$

$A = 32\text{cm}^2$

Therefore, the area of the rectangle is $32\text{cm}^2$

Judy needs to buy a glass table cover for a dinner party, which is 8 ft. long and 3 ft. wide. How much glass does she need to buy?

$24\ \textup{ft}^{2}$

$11\ \textup{ft}^{2}$

$32\ \textup{ft}^{2}$

$5\ \textup{ft}^{2}$

$36\ \textup{ft}^{2}$

Explanation

Explanation:

Remember to use the formula below to find area:

$Area = length\cdot width$

Since Judy needs enough glass to cover the whole table, this problem asks you to find the area. This means you need to multiply length and width to find the area, which is given in square feet, since each foot of glass is not only one foot long, but also one foot wide (a square).

Step 1: Plug in the numbers for the length and width

$Area = 8 \cdot 3$

Step 2: Solve

The short side of a rectangle measures inches, and the long side measures inches. What is its area?

Explanation

To find the area of a rectangle, multiply the length of the long side by the length of the short side.

The best answer is:

$3\times 7=21$

Find the area of a square if the perimeter is $4\pi$ .

$\pi^2$

$\pi$

$\frac{4}{\pi}$

Explanation

Write the formula for the area of a square.

In order to find the area of the square, we need to find the length of the side given the perimeter. There are four equal sides in a square. Divide the perimeter by 4.

$s=\frac{P}{4} = \frac{4\pi}{4} = \pi$

Substitute the side in the area formula.

$A=\pi^2$

A cube has a sidelength that measures 16 inches. What is the total area of two of its sides or faces?

None of the other answers.

Explanation

All faces of a cube have equal measurements and are squares. So if a cube has a sidelength that measures 16 inches, you know that all its sides measure 16 inches.

The surface area of one face of the cube is:

Since the question asks for the surface area of two faces of the cube we double the area found for one side:

Jon built a new garden with two sides equalling $15\textup{ ft}$ , and the other sides equalling $10\textup{ ft}$ . What is the area of Jon's new garden?