Can someone help me calculate the surface area of a water tank?

Question

The tank is 52 feet in diameter and 40 feet high with pitched roof at 5:1 slope. The structual surface area is 1.25 times the roof surface area.

Answer 1

roof slope

H1 = 52 / 5 = 10.4

break the tank into two cylinders

at the bottom of the roof slope.

one cylinder and one triangular cylinder.

roof length a ^2 +b^2 = c^2

c =sqrt (52^2+10.4^2) = 53.0

area of elliptical roof

A = pi r1 r2 = pi (53/2) (52/2) = 2165

cylinder height

H1 + H2 = 40

H2 = 40 -10.4 = 39.6

A= pi d H2

triangular wall area

A= 2 x 1/2  B H

B = 1/2 pi D = 52/2 x pi

Answer 2

Area of a cylinder is

A = pi * D * H = 3.14 * 52 * 40 = 6535 sq.ft.

Area of the bottom is

A = pi R^2 = 3.14 * (52/2)^2 = 2124 sq.ft.

A(stru) = (6535 + 2124) = 8658 sq.ft.

A(stru) = 1.25 * A (roof) = 8658 sq.ft.

A(roof) = 8658 / 1.25 = 6927 sq.ft.

A(tot) = 6926 + 8658 = 15485 sq.ft.