Answer:
r=3 ft
Step-by-step explanation:
it is similarity of two triangles
one
perpendicular side=10 ft
base=10/2=5 ft
second
perpendicular side=10-4=6 ft
Base r=?

Hello!
To find the area of a rectangular prism you do 2(lw + lh + wh)
Put in the values
2(9 * 2 + 9 * 6 + 2 * 6)
2(18 + 54 + 12)
2(84)
2 * 84 = 168
The answer is 168 cubic inches
Hope this helps!
B.yuri divided by n instead of n-1