Circles Diameter Radius

If you are given the radius, how can you calculate the diameter?

• Multiply the radius by 2

• Divide the radius by 2

• Add 2 to the radius

• Subtract 2 from the diameter

Find the radius of a circle who's diameter is 40 ft.

• 40ft

• 80ft

• 20ft

• 45ft

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm

find the radius of the circle

• 3 m

• 1.5 m

• 1.5 in

• 1.5 mm

What is the diameter?

• 5 in

• 10 in

• 3.14 in

• 15.84 in

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

• C = r²

• C = rd

• A = π·r²

• C = π·d

Find the circumference of the circle.

• 31.4 cm

• 78.5 cm

• 314 cm

• 15.7 cm

Find the circumference of the circle.

• 78.5 cm

• 15.7 cm

• 7.85 cm

• 19.6 cm

Find the circumference of the circle.

• 14.13 cm

• 63.56 cm

• 28.26 cm

• 127.17 cm

Find the area of the circle

• 43.96

• 153.86

• 87.82

• 307.72