I need the answers for math unit six surface area, lesson nine surface area of cylinders quick check, five questions

Answer 1

1. What is the formula for finding the surface area of a cylinder?
Answer: The formula for finding the surface area of a cylinder is SA = 2πr^2 + 2πrh, where r is the radius and h is the height of the cylinder.

2. If the radius of a cylinder is 5 inches and the height is 10 inches, what is the surface area of the cylinder?
Answer: SA = 2π(5)^2 + 2π(5)(10) = 2π(25) + 2π(50) = 50π + 100π = 150π square inches

3. A cylinder has a surface area of 100 square centimeters. If the radius is 3 centimeters, what is the height of the cylinder?
Answer: 100 = 2π(3)^2 + 2π(3)h
100 = 18π + 6πh
100 = 24π + 6πh
24π = 6πh
h = 4 centimeters

4. If the height of a cylinder is double its radius, what is the surface area of the cylinder?
Answer: Let the radius be r, then the height is 2r.
SA = 2πr^2 + 2πr(2r) = 2πr^2 + 4πr^2 = 6πr^2

5. If the surface area of a cylinder is 200 square units and the radius is 4 units, what is the height of the cylinder?
Answer: 200 = 2π(4)^2 + 2π(4)h
200 = 32π + 8πh
200 = 40π + 8πh
40π = 8πh
h = 5 units