Circle Perimeter and Area

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

• 2πr

• πr^2

• πd

• π/2r

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

• A = πr

• A = πr^2

• A = πd

• A = 2πr

If the radius of a circle is 5 cm, what is its circumference?

• 10π cm

• 15π cm

• 20π cm

• 25π cm

If the radius of a circle is 3.5 cm, what is its area?

• 7.07

• 38.465

• 21.98

• 12.25

If the circumference of a circle is 18π cm, what is its radius?

• 15

• 12

• 9

• 6

If the area of a circle is 64π cm², what is its radius?

• 4

• 16

• 8

• 32

What is the circumference of a circle with a diameter of 10 cm?

• 15.7 cm

• 20 cm

• 25.13 cm

• 31.42 cm

What is the area of a circle with a radius of 6.5 cm?

• 256.25

• 78.54

• 132.732

• 42.25

If the circumference of a circle is 36 cm, what is its diameter?

• 18 cm

• 12 cm

• 9 cm

• 5.7295779513082325

If the area of a circle is 100 cm², what is its diameter?

• 5 cm

• 20 cm

• 50 cm

• 11.28 cm