Circumference & Area Of Circles Practice Answers

Answer 1

1. What is the circumference of a circle with a radius of 5 units?

Circumference = 2 * π * radius
Circumference = 2 * π * 5
Circumference = 10π units

2. What is the area of a circle with a diameter of 8 units?

Radius = diameter / 2
Radius = 8 / 2
Radius = 4 units

Area = π * radius^2
Area = π * 4^2
Area = 16π square units

3. What is the circumference of a circle with a diameter of 12 units?

Radius = diameter / 2
Radius = 12 / 2
Radius = 6 units

Circumference = 2 * π * radius
Circumference = 2 * π * 6
Circumference = 12π units

4. What is the area of a circle with a circumference of 24π units?

Radius = Circumference / (2 * π)
Radius = 24π / (2 * π)
Radius = 12 units

Area = π * radius^2
Area = π * 12^2
Area = 144π square units

5. What is the circumference of a circle with an area of 36 square units?

Radius = √(Area / π)
Radius = √(36 / π)
Radius = √(36) = 6 units

Circumference = 2 * π * radius
Circumference = 2 * π * 6
Circumference = 12π units