Circumference

If my radius is 10ft, what is my diameter?

• 20ft
• 5ft
• 31.4ft
• 62.8ft

If my diameter is 19 inches, what is my radius?

• 38 inches
• 9.5 inches
• 59.66 inches
• 119.32 inches

If my diameter is 90cm, what is my circumference?

• 282.6cm
• 180 cm
• 90cm
• 565.2cm

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

• C = r²

• C = rd

• A = π·r²

• C = π·d

What does C represent in the formula:

C = π·d

• Pi

• Circumference

• Diameter

• Area

What does d represent in the formula:

C = π·d

• diameter

• radius

• pi

• 3.14

What is the circumference of a circle?

• the distance around a circle

• the area of a circle

• halfway through a circle

• a line through the center of a circle

Find the circumference of the circle.

• 31.4 cm

• 78.5 cm

• 314 cm

• 15.7 cm

Find the circumference of the circle.

• 38.47 cm

• 10.99 cm

• 43.96 cm

• 21.98 cm

The circumference of a circle is 45.53 yd. What is the diameter of that circle?

• 14.5 yd.

• 15.4 yd.

• 13.8 yd.

• 142.96 yd.