AGENDA:

DG 16 --- 10 minutes

Notes Lesson 2 Unit 5

DG 17 Mon

ACCEL PRECALC UNIT #5:INTRODUCTION TO TRIGONOMETRY LESSON #2: CONVERTING ANGLE MEASURES

EQ: How do you convert angle measures in radians to angle measure in degrees?

Converting angle measures:

deg

180

radians

Ex. Convert each angle measure. Reduce all fractions.

In Class Practice: Worksheet “ Angle Measure”

Calculator Conversions

Degrees, Minutes, Seconds

Ex. Convert degrees, minutes, seconds to decimal degrees and vice-versa.

50.106˚ 21˚15’22”

Arc length--- portion of a circle enclosed by 2 radii

s = rθ where θ is the radian measure of the central angle.

Ex. Find the arc length given a radius of 8 and a central angle of

4

3 .

6

84

3

s

s *** angle already in radian measure

Ex. A circle has a radius of 4 inches. Find the length of the major arc and the minor arc.

Major Arc :

Minor Arc :

3

4180

240

3

2180

120

ASSIGNMENT: textbook p. 292 – 293 #43 – 93 odd