what is the ratio of the surface areas for a pair of similar cylinders when the ratio of the heights is 1:3?

Question

i don't understand this at all!!

Answer 1

the surface area of similar figures varies directly as the square of their corresponding sides

so surface area(1)/surface area(2) = (1^2)/(3^2) = 1/9

so the surface area of the larger cylinder is 9 times that of the smaller.