Chapter 13 Section 3 Radian Measure

Central Angle Central Angle = Intercepted Arc (1,0) 1 unit

1 Radian Central Angle when the Radius = Arc Length 1 radian (1,0)

To convert Degrees to Radians or Radians to Degrees

To convert 1200 to Radians or Radians to Degrees

To convert 1200 to Radians or Radians to Degrees

Unit Circle For angles in standard position we use the variable q to show we are talking about an angle ( q (1,0) 1 unit

For any point on the unit circle, we can find the coordinates by using the angle in standard position and the rule (cos(q) , sin(q)) (cos(300) , sin(300)) 300 (1,0) 1 unit

Cosine and Sine of 30-60-90 triangles 2 1

Cosine and Sine of 30-60-90 triangles 2 1 300

Cosine and Sine of 45-45-90 triangles 1 450 1

Make a 30-60-90 triangle and look at the coordinates For angles with a terminal side not in the 1st quadrant Make a 30-60-90 triangle and look at the coordinates (- , ) 1200 (1,0) 1 unit

Make a 30-60-90 triangle and look at the coordinates For angles with a terminal side not in the 1st quadrant use the rule QI (+,+) QII (-,+) QIII (-,-) QIV(+,-) Make a 30-60-90 triangle and look at the coordinates 2100 (1,0) 1 unit (- ,- )

For angles with a terminal side not in the 1st quadrant use the rule QI (+,+) QII (-,+) QIII (-,-) QIV(+,-) U Try 3000 (1,0) 1 unit ( ,- )

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