Download presentation

1
**Area of Circles and Parts of Circles**

2
**Finding the area of a circle**

The area of a circle is found using the formula A = r2

3
**Practice Finding the area of a circle**

A = cm2 or cm2

4
**Practice Finding the area of a circle**

A = 6.734 cm2 or cm2

5
**Practice Finding the area of a circle**

Find the area of the shaded region A = 36 - 9 = 27 u2 or u2 3 6

6
**Practice Finding the area of a circle**

Find the area of the circle if the area of the square = 144 m2 The circle has a diameter of 12 m so A = 36 m2 or m2

7
**Practice Finding the area of a circle**

Find the area of the shaded region if the side of the square = 10 cm The area is 100 cm2 - 25 cm2 or cm2

8
**Practice Finding the area of a circle**

Find the area of the shaded region if the side of the square is 12 cm. The area is 144 cm2 - 4(9) cm2 or 30.9 cm2

9
**Finding the radius when area is known**

Since the formula for the area of a circle is A = πr2, the radius can be determined if the area is known. If A = 49π, then r2 = 49. If r2 = 49, then r = 7.

10
**Finding the radius when area is known**

Find the radius for each circle A = 144π A = 36π A = 81π A = 25π 5. A = 100π r = 12 r = 6 r = 9 r = 5 r = 10

11
**Finding the circumference when area is known**

To find the circumference when the area is known, first find the radius and then use it to find the circumference. A = 49π so r = 7 and d = 14 C = 14π

12
**Finding the circumference when area is known**

Find the circumference for each circle A = 144π A = 36π A = 81π A = 25π 5. A = 100π C = 24π C = 12π C = 18π C = 10π C = 20π

13
THE END

Similar presentations

OK

Circles Shape and Space. Formula for the area of a circle We can find the area of a circle using the formula radius Area of a circle = πr 2 Area of a.

Circles Shape and Space. Formula for the area of a circle We can find the area of a circle using the formula radius Area of a circle = πr 2 Area of a.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google