Question

a rectangular prism has dimensions 8ft by 3ft by 5ft what is the surface area of the prism

Answer 1

We have 6 faces of a rectangular prism

For the rectangle 8 ft x 3ft we have 2 equals

The area of one is

$A_1=l\times w=8\times3=24ft^2$

for the rectangle 8 ft x 5ft we have two equals

the area of one is

$A_2=l\times w=8\times5=40ft^2$

for the rectangle 5ft x 3ft we have two equals

the area of one

$A_3=l\times w=5\times3=15ft^2$

The surface area is

$SA=2(A_1)+2(A_2)+2(A_3)$$SA=2(24)+2(40)+2(15)$$SA=158ft^2$