how to find surface area of a cylinder with respect to r(radius) and h(height)?

Answer 1

well, you know that the surface has two circular ends, and a curved lateral surface.

If you unroll the cylinder, the curved surface is just a rectangle as wide as the circumference of the cylinder (2πr) and height h. So, its area is 2πrh.

Add that to the two circles at the ends and you have

A = 2πr^2 + 2πrh = 2πr(r+h)