What is the surface area of a cylinder of a radius of 10 and height of 9?

Answer 1

The total surface area is about 1193.81 square units.

The lateral surface area is found by multiplying the height (9) times the circumference (2 x pi x r). Since r = 10 we get:
9 x 2 x 10 x pi = 180pi = approx. 565.49

If we are to include the top and bottom of the cylinder, we must add to the lateral surface area the areas of the circles at the top and bottom = 2 x pi x r^2
= 2 x pi x 100
= 200pi = approx. 628.32

So, combining the top, bottom and lateral surfaces we get 380pi.