It should be 715, i don’t understand why that isn’t one of the choices.
you’re supposed to multiply everything
I think the answer is that they are parallel
Find the diameter then multiply by pi
12 - 3x + 4 ( 10 - 2^3 )
12 - 3 ( 2/3 ) + 4 ( 10 - 2^3 )
12 - 2 + 4 ( 10 - 8 )
12 - 2 + 40 - 32
10 + 8
18
The area of the base (six triangles with a base 15m and a height 7.5√3m):

The area of side walls (six triangles with a base 15m and a height 12m)

The surface area: