Question

A rectangular and two circular cut-outs of metal sheet of negligible thickness are used to make a closed cylinder. The rectangular cut-out ha a height of 18 cm. Each circular cut-out has a radius of 5.2 cm. Calculate in terms of area of π, the surface area of the cylinder.

Answer 1

assuming the rectangle is long enough to wrap around the cylinder,

a = πr^2 + πr^2 + 2πrh = 2πr(r+h)

Now just plug in r and h.

Answer 2

241.28pie