2 Using Trigonometry in a Right Triangle We were limited to Acute AnglesWe can extend Trigonometry toAngles of Any Measureby placing those angles inthe coordinate planeWe do this by using reference angles,Acute Angles measured to the x-axis.
3 The terminal sideis rotated counter-clockwise.135°Angles are Placed with one sidecalled the initial sideon the positive x-axis.
4 The terminal sideis rotated counter-clockwise.135°45°A Reference Angle is measuredto the x-axis.
5 The terminal sideis rotated counter-clockwise.225°45°A Reference Angle is measuredto the x-axis.
6 The terminal sideis rotated counter-clockwise.315°45°A Reference Angle is measuredto the x-axis.
7 If the terminal side is rotated clockwise, the angle measure is Negative.45°A Reference Angle is measuredto the x-axis.Always Positive.-45°