This document provides definitions and formulas for calculating the area of circles and sectors of circles. It defines area of a circle as πr^2, central angle as the angle formed by two radii with its vertex at the center of the circle, and sector of a circle as the region enclosed by two radii and the arc joining their endpoints. It gives the formula to calculate the area of a sector as (measure of central angle/360) * πr^2 and works through examples of finding the areas of circles and sectors.

2. A = 2.52πA = 122π

3. A = 6.25π(left in terms of Pi)A = 144π(left in terms of Pi)

4. A = 3.14 x 6.25A = 3.14 x 144

5. A = 19.625 in2A = 452.16 m2

6. Find the area for each circle. Use 3.14 for π

7. r = 2d = 4r = 4d = 8

8. A = π r2A = π r2____________

9. A = 42πA = 22π

10. A = 16π(left in terms of Pi)A = 4π(left in terms of Pi)

11. A = 3.14 x 16A = 3.14 x 4

13. A = _______________A = _______________

14. A = _______________A = _______________

15. Find the area for each circle. Use 3.14 for π

16. A = π r2A = _______________

17. A = _______________A = _______________

18. A = _______________A = _______________To find the area of the sector of a circle:<br />90<br />A = m πr2(m = measure of angle of<br />2mm 360the central angle)<br />A = m πr2<br /> 360<br />A = _____________<br />A = _____________<br />A = _____________<br />120<br />3mm<br />A = m πr2<br /> 360<br />A = _____________<br />A = _____________<br />A = _____________<br />1mm<br />180<br />A = m πr2 <br /> 360 <br />A = _____________<br />A = _____________<br />A = _____________<br />