Circle Math Quiz

What is the formula to calculate the area of a circle?

• A = πr^2

• A = 2πr

• A = πd

• A = r^2

Find the area of a circle with a radius of 5 units.

• 20π

• 30π

• 10π

• 25π

What is the formula to calculate the circumference of a circle?

• pi * radius

• 2 * pi * radius

• radius * radius

• 2 * radius

Find the circumference of a circle with a diameter of 10 units.

• 20.2832

• 15.7079

• 31.4159

• 25.1327

What is the formula to calculate the radius of a circle?

• radius = diameter / 2

• radius = diameter * 2

• radius = diameter + 2

• radius = diameter

Find the radius of a circle with an area of 78.5 square units.

• 2.50

• 10.00

• 3.14

• 5.00

What is the formula to calculate the diameter of a circle?

• 2 * radius

• radius + radius

• radius * 2

• radius / 2

Find the diameter of a circle with a circumference of 31.4 units.

• 5

• 15

• 10

• 20

If the radius of a circle is 3 units, what is its area?

• 6π

• 9π

• 12π

• 18π

If the circumference of a circle is 18.84 units, what is its diameter?

• 12

• 3

• 6

• 9