Topic 8.5 Circumference

What two formulas can you use to find the circumference?

• C = π·d

• C = π·r²

• C = 2·π·r

• C = d²

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 this circle?  Round to the nearest tenth.

• 3.14 cm 

• 37.7 cm

• 24 cm

• 68.4 cm

A cruise ship has a large, circular window. It has a diameter of 6 meters. What is the window's perimeter? (Use 3.14 for pi.)

• 21.25 m²

• 19.55 m²

• 15.36 m²

• 18.84 m

Find the circumference. Round to the nearest tenth.

• 18.8 cm.

• 75.4 cm.

• 37.7 cm.

• not enough information

Find the circumference of the circle. Round to the nearest tenth.

• 113.0 in.

• 1017.4 in.

• 254.3 in.

• 56.5 in.

Find the circumference of the circle.

• 113.04 in

• 1017.36 in

• 254.34 in

• 56.52 in

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