we gots a triangular prism+ rectangular prism
easiest way is base times heigth and treat the triangle+rectangle on the side as the base
so
find the area of the side
the rectangle bit is area=7.5 times 7=52.5
the triangle bit is 1/2 times 7.5 times 7=26.25
total area is 52.5+26.25=78.75
and the height is 8
volume=8 times 78.75=630 cubic feet
answer is C
