Understanding the Area of a Circle

What is the formula for calculating the area of a circle?

• 2πr

• 2πr²

• πr²

• πd

If the diameter of a circle is 10, what is the radius?

• 20

• 5

• 15

• 10

Given a circle with a diameter of 10, what is the area in terms of π?

• 25π

• 10π

• 50π

• 100π

If the area of a circle is 144π, what is the radius?

• 16

• 12

• 14

• 10

For a circle with an area of 144π, what is the diameter?

• 12

• 24

• 36

• 48