1. 6.1 Angles and Radian Measure Objective: Change from radian to degree measure and vice versa. Find the length of an arc given the measure of the central angle. Find the area of a sector.

2. Change 36° to radian measure in terms of π.

3. A S T C θ O A H 135° 1

4. Given a central angle of 147°, find the length of its intercepted arc in a circle of radius 10 cm. Round to the nearest tenth. First change the degree measure into radians. radians Second use the formula s = rθ. Where s is the arc length, r is the radius, and θ is the measure of the central angle in radians. s = rθ

6. A = πr 2 Typical formula for area of a circle. However, a sector is a portion of the circle. When measured in radians, it is a portion of 2π. So we get a portion of the area. A = πr 2

8. Assignment 6.1 Practice Worksheet Unit Circle Worksheet