7th Grade Math

Lesson 1B Volume 559

Volume of a Rectangular Prism

Find the volume of the rectangular prism.

5 cm

4 cm

V = wh Volume of a prism 3 cm

V = 5 · 4 · 3  = 5, w = 4, and h = 3

V = 60 Multiply.

The volume is 60 cubic centimeters or 60 cm^3.

a. Find the volume of the rectangular

3 m

9.5 m 5 m

prism at the right.

MARKETING A company makes lunch boxes in two different

sizes. Which lunch box holds more food?

7.5 in.

110 in.

3 .7 5 in. 8 in.

9 .5 in.

3 .7 5 in.

Find the volume of each lunch box. Then compare.

Lunch Box A

V = wh

V = 7.5 · 3.75 · 10

V = 281.25 in^3

Lunch Box B

V = wh

V = 8 · 3.75 · 9.5

V = 285 in^3

Since 285 in^3 > 281.25 in^3 , Lunch Box B holds more food.

b. PACKAGING A concession

4 in.

4.5 in. 4 in.

5 in.

3 .5 in.^3.^5 in.

#PY
" #PY
#

stand serves peanuts in two

different containers. Which

container holds more peanuts?

Justify your answer.

Decomposing Figures Decomposing Figures

You can think of the volume

of the prism as consisting

of three congruent slices.

Each slice contains the

area of the base, 20

square centimeters, and a

height of 1 centimeter.

Real-World Link

Lunch boxes from the

1950s and 1960s

sometimes sell for

thousands of dollars

at auctions.

RR

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