Circumference The distance around a circle or Find

Circumference The distance around a circle

or

Find the circumference to the nearest tenth. 1. 2.

Circumference Writing your answer in terms of π EX: What is the exact measure of the circumference?

ON YOUR OWN: What is the exact measure of the circumference?

3. The circumference of a half dollar is about 96 millimeters. Find the diameter of the coin to the nearest tenth. d ≈ 30. 6 mm

4. A circular flower garden has a circumference of 20 feet. Find the radius of the garden to the nearest hundredth. r ≈ 3. 18 ft

GUIDED PRACTICE Simplify (Round to the nearest tenth): 1. 2. 3. 26. 9 6. 3 23. 6

Arc Length a fraction of the circumference of a circle e c ie portio t r pa sect p n ion

Arc Length Corollary the ratio of the length of an arc to the circumference is equal to the ratio of the measure of the arc to 360º * *

Example 1 Find the length of arc AB to the nearest hundredth. A 90º 15 ft B A 23. 55 ft

Example 2 Find the length of arc AB to the nearest hundredth. A 40º 6 m B A 4. 19 m

Example 3 A Find the measure of arc AB to the nearest degree. 18. 84 m 9 m B m. AB = 120º

Example 4 Find the radius of circle N to the nearest foot. A 1. 57 ft N 45º B r ≈ 2 ft

Example 5 Find the circumference of circle Q. A 41. 87 cm 200º Q B C ≈ 75. 37 cm