117 Views

Download Presentation
## Warm-UP

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Warm-UP**14 cm • Find the diameter or radius: a. r = 7 cm; d = ░ b. d = 5 in; r = ░ c. r = 4.2 ft; d = ░ • Simplify (round to the nearest tenth): a. π•20= b. 2•π•7= 2.5 in 8.4 ft 62.8 44.0**Circumference**6.7 Arc Length**Circumference**Circumference The distance around a circle**1.**2. Find the circumference to the nearest tenth. 33 m 14.3 in. C = 89.8 in C = 103.7 m**Exact Measure**Circumference EX: What is the exact measure of the circumference? Writing your answer in terms of π 14.3 in.**ON YOUR OWN:**What is the exact measure of the circumference? 33 m**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**26.9 Simplify (Round to the nearest tenth): 1. 2. 3. 6.3 23.6**Arc Length**piece portion a fraction of the circumference of a circle part section**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 * ***Guided Practice**Complete How Do You Find Arc Length?**A**Example 1 90º B 15 ft Find the length of arc AB to the nearest hundredth. A 23.55 ft**Example 2**A 40º B 6 m Find the length of arc AB to the nearest hundredth. A 4.19 m**A**18.84 m Example 3 B 9 m Find the measure of arc AB to the nearest degree. mAB = 120º**A**Example 4 1.57 ft 45º B N Find the radius of circle N to the nearest foot. r ≈2 ft**A**Example 5 41.87 cm Q 200º B Find the circumference of circle Q. C ≈75.37 cm**Homework**p. 226 (1-10, 17-19) Show ALL Work for Credit!!