Circles: Radius, Diameter, and Circumference

Circle Terms

100

The distance from the center of a circle to the outside, also half of the diameter

radius

200

The line that goes through the center of the circle from one side to the other.

diameter

300

The distance around the outside of a circle.

circumference

400

The total amount of space inside of a circle

area

500

3.14 or 22/7

Pi

Finding Radius(find the radius for all)

100

The Diameter of this circle is 5 cm.

2.5 cm

200

The diameter is 12 inches.

6 inches

300

The diameter of this circle is 27 cm.

13.5 cm

400

The diameter of this circle is 437 units.

218.5 units

500

The diameter of this circle is 0.325 ft.

0.1625 ft

Finding Diameter (Find Diameter for all)

100

The radius of this is 5 miles.

10 miles

200

The radius of this circle is 2.5 yards.

5 yards

300

The circumference of this circle is 15.7 cm.

5 cm

400

The circumference of this circle is 18.84 inches.

6 inches

500

The circumference of this circle is 194.68 ft.

62 ft

Finding Circumference(Find Circumference for all)

100

The diameter for this circle is 10 cm. Use 3.14 for Pi.

31.4 cm

200

The diameter for this circle is 13 yards. Use 3.14 for Pi.

40.82 yards

300

The diameter of this circle is 25 yards. Use 3.14 for Pi.

78.5 yards

400

The radius for this circle is 45 inches. Use 3.14 for Pi.

282.6 inches

500

The diameter for this circle is 3285 cm. Use 3.14 for Pi.

10,314.9 cm

Finding Area(Find area for all)

100

The radius of this circle is 2 feet. Use 3.14 for Pi.

12.56 ft²

200

The radius of this circle is 3 inches. Use 3.14 for Pi.

28.26 in²

300

The radius of this circle is 21 cm. Use 3.14 for Pi.

1384.74 cm²

400

The diameter of this circle is 104.8 meters. Use 3.14 for Pi. Round the answer to the nearest tenth.

8,621.7 m²

500

The diameter of this circle is 7 inches. Use 3.14 for Pi. Round your final answer to the nearest tenth.

38.5 in²