Question

two similar cylinders have surface areas of 40pi square feet and 90pi. What is the ratio of the height of the large cylinders to the height of the small cylinder?

Answer 1

The ratio of heights  = ratio of the square roots of the areas because area is 2 dimensional and height is one dimensional.

so required ratio is  sqrt 40pi :   =  sqrt40:sqrt80 =  sqrt1: sqrt2 = sqrt (1/2) = 0.7071  to 4 significant figures