Circumference and Diameter

Find the diameter of a circle if its radius is 7.5 meters. (Type the answer including the units)

Find the diameter of a circle if its radius is 8.42 inches. (Type the answer including the units)

Find the radius of a circle if its diameter is 12.8 feet. (Type the answer including the units)

What is the diameter?

• 8

• 16

• 10

• 4

Steven purchases a bowl. The diameter of the
bowl is 14 cm. What is the circumference of the 
bowl?

• 28 cm

• 43.98 cm

• 87.96 cm

• 7 cm

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

• 282.6cm

• 180 cm

• 90cm

• 565.2cm

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

• 20ft

• 5ft

• 31.4ft

• 62.8ft

The homeowners association wants to enclose the playground in a fence. So they need to figure out how much fencing will they need to purchase. Is this question finding the area or the circumference of a circle?

• area

• circumference

• neither

What two formulas can you use to find the circumference?

• C = π·d

• C = π·r²

• C = 2·π·r

• C = d²