1. CIRCLES Lesson 9-6

2. Circles A circle is a set of points that are the same distance from a given point, called the center

3. Circles Circumference—the distance around The circle

4. Circles Circumference—the distance around the circle Chord—a segment whose endpoints are on the circumference.

5. Circles Circumference—the distance around the circle Diameter—the longest chord in a circle. It passes through the center. Chord—a segment whose endpoints are on the circumference.

6. Circles Circumference—the distance around the circle Diameter—the longest chord in a circle. It passes through the center. Radius—A segment that has one endpoint in the center and the other endpoint on the circumference. It is half the length of the diameter. Chord—a segment whose endpoints are on the circumference.

7. Circles When measuring parts of circles, we often use a constant called pi. It is a greek letter that has a value of approximately 3.14 and it looks like this:

8. Circles The circumference of a circle is pi multiplied by the diameter.

9. Circles The circumference of a circle if pi multiplied by the diameter. What is the circumference of a circle whose diameter is 7 cm? C = 3.14 (7) C = 21.98 cm

10. Try This Find the circumference when given the following: d = 12 inches r = 2 feet

11. Try This Find the circumference when given the following: d = 12 inches37.68 inches r = 2 feet

12. Try This Find the circumference when given the following: d = 12 inches37.68 inches r = 2 feet12.56 feet

13. Try This Find the circumference: 5 cm 5 in

14. Try This Find the circumference: 5 cm 5 in 15.7 cm

15. Try This Find the circumference: 5 cm 5 in 15.7 cm 31.4 in