Reference Angles
Reference Angle: A positive acute angle formed by the terminal side of 𝜃 and the closest side of the 𝑥-axis.
We often label the reference angle as 𝛼 or 𝜃′
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Find the reference angle for each of the following:
A) 4𝜋5
B) −5𝜋3
C) 9𝜋4