Expressions, Equations, and Relationships>Writing Equations for Area and Volume of Shapes with Rational Dimensions(TEKS.Math.6.8.C)

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Texas 6th Grade Math › Expressions, Equations, and Relationships>Writing Equations for Area and Volume of Shapes with Rational Dimensions(TEKS.Math.6.8.C)

Questions 1 - 3
1

A parallelogram has a base of 7.2 meters and a height of 4.5 meters. Which equation shows the area of the parallelogram?

$A = 2(7.2 + 4.5)$

$A = 7.2 \times 4.5$

$A = \tfrac{1}{2} \times 7.2 \times 4.5$

$A = 7.2 \times 7.2$

Explanation

The area of a parallelogram is $A = b \times h$. Substituting: $A = 7.2 \times 4.5$.

2

A trapezoid has bases of 9 inches and 6.4 inches and a height of 5 inches. Which equation represents the area of the trapezoid?

$A = (9 + 6.4) \times 5$

$A = \tfrac{1}{2}(9 + 6.4)$

$A = \tfrac{1}{2}(9 + 6.4) \times 5$

$A = \tfrac{1}{2}(9 \times 6.4) \times 5$

Explanation

The area of a trapezoid is $A = \tfrac{1}{2}(b_1 + b_2)h$. Substituting: $A = \tfrac{1}{2}(9 + 6.4) \times 5$.

3

A right rectangular prism has length 3.5 cm, width 2 cm, and height 4.2 cm. Which equation represents the volume of the prism?

$V = 3.5 \times 2 \times 4.2$

$V = 2(3.5 + 2 + 4.2)$

$V = 3.5 \times 2 + 4.2$

$V = \tfrac{1}{2} \times 3.5 \times 2 \times 4.2$

Explanation

The volume of a right rectangular prism is $V = l \times w \times h$. Substituting: $V = 3.5 \times 2 \times 4.2$.