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