How do you find the related acute angle?

1 Answer
Johnson Z.
Nov 26, 2015

The related acute is an acute angle (#<90^@#) that can be found between the terminal arm and the x-axis when the terminal arm is in quadrants 2, 3, or 4. There is no related acute angle if the terminal arm lies in quadrant 1.

Here are some examples:

http://slideplayer.com/slide/4747145/

If the terminal arm is in quadrant 2, do #180^@# minus the principle angle to find the related acute angle.

If the terminal arm is in quadrant 3, do the principle angle minus #180^@# to find the related acute angle.

If the terminal arm is in quadrant 4, do #360^@# minus the principle angle to find the related acute angle.

Related questions
See all questions in Angle Basics and Measurements
Impact of this question
71602 views around the world
You can reuse this answer
Creative Commons License