2. 6.7Circumference and Arc Length Theorem 6.19 The circumference C of a circle is C = ____ or C = _____, where d is the diameter of the circle and r is the radius of the circle. dd  r d r dd

3. Example 1 Use the formula for circumference Find the indicated measure. a.Circumference of a circle with radius 11 meters b.Radius of a circle with circumference 18 yards Solution 6.7Circumference and Arc Length

4. Checkpoint. Complete the following exercise. 1.Find the circumference of a circle with the diameter 23 inches. 6.7Circumference and Arc Length

5. Arc Length Corollary In a circle, the ratio of the length of a given arc to the circumference is equal to the ratio of the measure of the arc to 360 o. P r A B 6.7Circumference and Arc Length

6. Example 2 Find and use arc lengths Find the indicated measure. a.Arc length of AB P A B 6.7Circumference and Arc Length

7. Example 2 Find and use arc lengths Find the indicated measure. b.mRS 6.7Circumference and Arc Length Q S R Write equation. Substitute. Multiply each side by _____. Use a calculator.

8. Checkpoint. Find the indicated measure. 2.Arc length of AB 6.7Circumference and Arc Length P A B

9. Checkpoint. Find the indicated measure. 6.7Circumference and Arc Length 3.Circumference of Z Z X Y

10. 6.7Circumference and Arc Length Pg. 236, 6.7 #2-24 even