Circumference and Area of Circles

1. Find the circumference when the d=7in. Round to the nearest whole number.

_____ inches

2. Find the circumference when the r=3.2 inches. Round to the nearest whole number.

____ inches

3. Find the area when d= 10.5 cm.

___ square cm.

4. Find the area when r = 18.

___ sq cm.

5. Find the radius of a circle that has a circumference of 340 cm.

____ cm

6. Find the diameter of a circle that has a circumference of 74 cm.

_____ cm

7. Find the radius of a circle that has an area of 212 square inches.

____ inches

8. Find the diameter of a circle that has an area or 100 square cm.

____ cm

9. Your answer should be slightly off because we are using 3.14 (which is an approximation of pi).

What did we use as an approximation?

• 3.14

• 2.58

• 1.23

• 8.24

10. The area of a circle is 195 square inches. Find the circumference of the circle.

_____ inches