Area & Circumference of Circles

What is the line called that goes from one side of a circle to the other and passes through the center?

• Radius

• Circumference

• Chord

• Diameter

Which formula can be used to find the area of a circle?

• π * D

• D / 2

• π * R^2

• 2π * R

If you know the radius of a circle, which formula would you use to find the circumference?

• C = D / 2

• C = R^2

• C = 2π * R

• C = π * D

A circle has a radius of 4 cm. What is its area?

• 16π square cm

• 8π square cm

• 25.1 square cm

• 50.3 square cm

If a circle's diameter is 10 cm, what is its circumference?

• 31.4 cm

• 50.3 cm

• 15.7 cm

• 78.5 cm