1. Objectives: You will be able to convert between radians and degrees, find arc lengths. You will be able to define a radian. Agenda: 1.Do Now 2.Angles-Vocabulary 3.Measuring in degrees and DMS 4.Radian Investigation 5.Wrap up- Converting to radians and degrees Wednesday, December 3, 2014

2. Radian Measure Investigation- Wrap up. So what’s the point???? 2   6.28, there are just over six radius lengths in a full circle.

3. Radian Measure Because the radian measure of an angle of one full revolution is 2 , you can obtain the following.

4. Conversion between Degrees and Radians Using the basic relationship  radians = 180º, To convert degrees to radians, multiply degrees by (  radians) / 180  To convert radians to degrees, multiply radians by 180  / (  radians)

5. Convert to the other form … a)π/3 b)π/12  55 o  -5 π/6  -75 o

6. Unit Circle

7. Length of a Circular Arc Let r be the radius of a circle and  the non- negative radian measure of a central angle of the circle. The length of the arc intercepted by the central angle is s = r   O s r

8. Finding Arc Length A circle has a radius of 4 inches. Find the length of the arc intercepted by a central angle of 240 .

9. Find the perimeter of a 60º slice of a large pizza with a radius of 7inches?

10. Classwork pgs. 356-357 25-38,59-66