Question

The ratio between the curved surface area and the total surface area of a right circular cylinder is 1:2. What is the ratio between the height and radius of the cylinder

Answer 1

given, csa : tsa of cylinder = 1:2

          2πrh / 2πr(r+h)  = 1/2

             h/(r+h) = 1/2

 by cross multiplication, we get

             2h = r+h

             2h-h = r

therefore h=r

by calculating, we get height is equal to radius. then ratio of their height and radius is      

     height of cylinder : radius of cylinder = 1:1