Circles, Radius, Diameter, Circumference, and Area

The diameter of a circle is 11 yds. What is the radius?

• 11

• 22

• 6.5

• 5.5

A circle has a diameter of 8cm. Find the circumference of the circle.

• 25.12 cm

• 4 cm

• 16 cm

• None of the above

If the diameter of a circle is 142 millimeters, then what is the radius?

• 71 mm

• 45.8 mm

• 42 mm

• 203.25 mm

Find the circumference of a circle with a diameter of 10 m.

• 31.4 m

• 314 m

• 3.14 m

• 3140 m

the radius of the circle is 22 cm, what is the circles diameter?

• 11 cm

• 44 cm

• 22 cm

• 7 cm

A circle has a diameter of 6ft. What is the circumference of the circle?

• 18.84 ft

• 113.04 ft

• 36 ft

• None of the above

Which equation describes how the radius of a circle, r, and its diameter, d, are related?

• r = d ⋅ 2

• r = (1/2)d

• d = (1/2)r

the ratio of a circles circumference to its diameter

• area

• circumference

• pi

• radius

PI equals

• 22/7

• 3.14...

• both

• neither

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

• 20 ft

• 5 ft

• 31.4 ft

• 62.8 ft