Question

for painting a hollow cylinder what is required. ​

Answer 1

Surface Area

Surface area is the measurement of all exposed area of a solid object.

Hollow Cylinder

An object bounded by two co-axial cylinders of the same height and different radii is called a ‘hollow cylinder’.

Let R and r be the outer and inner radii of the cylinder. Let h be its height.

C.S.A of the hollow cylinder = outer C.S.A. of the cylinder + inner C.S.A. of the cylinder

= 2πRh +2πrh