Exercise 5 Page 657

We are given a rectangular pyramid with a volume of 448 cubic inches. The base's edge is 12 inches and the base's length is 8 inches. We want to find the height of this pyramid. Let's first recall the formula for the volume of a pyramid. V=1/3BhHere, B is the area of the base, and h is the height of the pyramid. Since the base is a rectangle, the base's area B is the product of the base edge and the base's length. Let's find this area! B = 12( 8) = 96 The base's area is 96 square inches. Our pyramid has a volume of 448 cubic inches. Let's substitute this values into the formula for the volume of a pyramid. That way, we will get an equation for h. Then, let's solve this equation!

V=1/3Bh

SubstituteII

V= 448, B= 96

448=1/3( 96)h

MoveLeftFacToNumOne

a* 1/b= a/b

448=96/3h

CalcQuot

Calculate quotient

448=32h

DivEqn

.LHS /32.=.RHS /32.

448/32 = h

CalcQuot

Calculate quotient

14 = h

RearrangeEqn

Rearrange equation

h = 14

The height is 14 inches.