Answer:
SA = 3,140 ft³
Step-by-step explanation:
We have:
h = 40 ft
2r = 20 ft → r = 10 ft
Substitute to the formula of a Surface Area of a cylinder:
[tex]SA=2\pi r^2+2\pi rh[/tex]
[tex]SA=2\pi(10^2)+2\pi(10)(40)=2\pi(100)+2\pi(400)\\\\=200\pi+800\pi=1,000\pi\ ft^3\\\\\pi\approx3.14\to SA\approx1,000(3.14)=3,140\ ft^3[/tex]
