Presentation is loading. Please wait.

Presentation is loading. Please wait.

Radian Measure That was easy

Similar presentations


Presentation on theme: "Radian Measure That was easy"— Presentation transcript:

1 Radian Measure That was easy
What does that mean? One radian is the measure of a central angle of a circle that intercepts an arc whose length equals a radius of the circle. Central angle intercepts an arc whose length, s, is inches in a circle that has a radius length of 12 inches. Find r = 12 General Formula or or That was easy

2 Converting from Degrees to Radians
To change from degrees to radians, multiply the number of degrees by Convert the following angle measurements from degrees to radians.

3 Converting from Radians to Degrees
To change from radians to degrees, multiply the number of radians by Convert the following angle measurements from radians to degrees.

4 Comparing Degrees and Radians
The radius of a circle is 12 centimeters. What is the number of centimeters in the length of the minor arc intercepted by a central angle that measures 135o? Method 1 Method 2 r = 12 s How about that. You get the same answer either way.

5 Homework Page : 4 – 22 Even Numbers

6 Angles in Standard Position
Let’s look at a diagram that will explain what an angle in standard position is. y If the terminal side rotates in a counterclockwise direction, the angle is positive. Terminal Side -x x Initial Side If the terminal side rotates in a clockwise direction, the angle is negative. -y

7 Drawing Angles in Standard Position
Draw the following angles. 360o 180o 270o

8 Reference Angles The reference angle is the acute angle whose vertex is the origin and whose sides are the terminal side of the original angle and the x-axis. The reference angle is denoted as Quadrant I Quadrant II Quadrant III Quadrant IV

9 Finding Reference Angles
For each angle given in radian measure, find the measure of the reference angle in radians. That was easy

10 Coterminal Angles A positive angle and a negative angle are coterminal angles if the sum of the absolute values of their degree measures is 360 or a multiple of 360. y Example 1 A rotation angle measures 210o. What is the measurement of its coterminal angle? -x x Example b A rotation angle measures 300o. What is the measurement of its coterminal angle? -y

11 Also name the Coterminal Angle for each angle
Homework Page 405: All Also name the Coterminal Angle for each angle

12 Comparing Degrees and Radians
The radius of a circle is 12 centimeters. What is the number of centimeters in the length of the minor arc intercepted by a central angle that measures 135o? Method 1 Method 2 r = 12 s How about that. You get the same answer either way.

13 Arc Length and Radians

14 Homework Page 405: 28 – 40 Even Numbers


Download ppt "Radian Measure That was easy"

Similar presentations


Ads by Google