Circle Unit Review

Radius

100

If the diameter is 50 feet, what is the RADIUS?

25 feet

200

If the circumference is 62.8 yards, what is the RADIUS as a decimal rounded to the nearest tenth?

10 yards

300

If the circumference is 12pi feet, what is the RADIUS in terms of pi?

6 feet

400

If the area is 225pi mm², what is the RADIUS in terms of pi?

15 mm

Diameter

100

If the radius is 30 yards, what is the DIAMETER?

60 yards

200

If the circumference is 86 mm, what is the DIAMETER rounded to the nearest tenth?

27.4 mm

300

If the area is 196pi cm², what is the DIAMETER in terms of pi?

28 cm

400

If the area is 95 in², what is the DIAMETER rounded to the nearest tenth?

11 in

Circumference

100

If the diameter is 10 feet, what is the CIRCUMFERENCE in terms of pi?

10pi feet

200

If the diameter is 18 mm, what is the CIRCUMFERENCE rounded to the nearest tenth place?

56.5 mm

300

If the radius is 3.7 in, what is the CIRCUMFERENCE as a decimal rounded to the nearest tenth?

23.2 in

400

If the area is 5.5 ft², what is the CIRCUMFERENCE rounded to the nearest tenth?

8.3 ft

Area

100

Find Area when Radius = 21 cm 

Round to the nearest tenth.

1384.7 cm

200

If the diameter is 9.1 mm, what is the AREA as a decimal rounded to the nearest tenth?

65 mm²

300

What is the area of a circle with a diameter of 100 mm as a whole number?

7,850 mm²

400

If the circumference is 48pi mm, what is the AREA in terms of pi?

576pi mm²

Proportional Relationships with Circles

100

Is the radius proportional to the diameter?

If yes, what is the COP?

If no, Why not?

YES

The COP is 2 or 1/2

200

Is the radius proportional to the area?

If yes, what is the COP?

If no, why not?

NO

There is no COP, the equation has radius squared

300

Is the diameter proportional to the circumference?

If yes, what is the COP?

If no, why not?

YES

The COP is pi (3.14)

400

Is the radius proportional to the circumference?

If yes, what is the COP?

If no, why not?

YES

The COP is 2pi