Question

Wesley wants to paint his company's building an awesome shade of candy-apple red. If the building is shaped like a rectangular prism that's 42 feet tall, 18 feet wide, and 30 feet long, what will it cost him to paint the outside walls and roof if paint costs $10 per square foot?

Answer 1

Calculate the surface area of the bulding:

The surface area of a rectangular prism = 2 (lw) + 2 (lh) + 2 (wh)

Where:

l = length = 30

h= height = 42

w = width = 18

Since the bottom of the building is not painted. we only ad 1 lw

SA = lw + 2lh + 2 wh

Replacing with the values given:

SA = (30 x 18 ) + 2 ( 30x42) + 2 ( 18 x 42 )

SA = 540 + 2(1260 )+ 2 (756)

SA = 540 + 2520 + 1512

SA = 4,572 square foot

Multiply the surface area by the cost per square foot:

$10 x 4572 = $45,720