In this question , it is given that we have a cylinder with with a radius of 9 and a surface area of approximately 791.68 units square.
The formula of surface area of cylinder is

Substituting the values of A and r, we will get

So the height of the cylinder is 5 units .
Answer:
10
Step-by-step explanation:
5 choose 2 is 5x4/2, which is 20/2, which is 10.