Exercise 13 Page 645

Use the formula for the volume of a prism.

20.4 cubic millimeters

Practice makes perfect

The given solid is a triangular prism.

The volume of a prism can be calculated using the following formula. V= B h Here, B is the area of a prism's base and h is the prism's height. Note that the base is a right triangle, so we can calculate its area using the formula for area of a triangle.

B=1/2bh

SubstituteII

b= 2.5, h= 3.4

B=1/2( 2.5)( 3.4)

▼

Simplify right-hand side

MoveRightFacToNumOne

1/b* a = a/b

B=8.5/2

CalcQuot

Calculate quotient

B= 4.25

The area of the base is 4.25 square millimeters. The prism's height equals 4.8 millimeters. Let's substitute these values into the formula and solve for V.

V=Bh

SubstituteII

B= 4.25, h= 4.8

V=( 4.25)( 4.8)

Multiply

V=20.4

The volume of the prism is 20.4 cubic millimeters.