Question

The surface area of the prism is

Answer 1

Surface area is the area of all the surfaces, that's why it's called surface area...so let's calculate the area of the bottom rectangle, the front rectangle, back rectangle, and the two triangles on the sides.

Bottom Rectangle:

$\sf A=lw$
Length = 12 yd, Width = 9 yd

$\sf A=(12)(9)$

$\sf A=108~yd^2$

Front Rectangle:

$\sf A=lw$
Length = 12 yd, Width = 5 yd

$\sf A=(12)(5)$

$\sf A=60~yd^2$

Back Rectangle:

$\sf A=lw$
Length = 12 yd, Width = 8 yd

$\sf A=(12)(8)$

$\sf A=96~yd^2$

Triangle:

$\sf A=\dfrac{1}{2}bh$
Base = 9 yd, Height = 4 yd

$\sf A=\dfrac{1}{2}(9)(4)$

$\sf A=12~yd^2$

Remember we have two of these triangles.

Now let's add up all the measurements:

$\sf 108+60+96+12+12=\boxed{\sf 288~yd^2}$