1. Unit Circle / Circular Functions
terminal
arm/ side
initial arm/ side
Standard Position of
Initial arm lays
on the x-axis
the origin

2. e)
f)
=2
= -3.5

3. Reference Angle
Acute angle formed between the terminal arm of
an angle and the nearest x-axis.

4. Coterminal Angles
angles which share the same terminal side/ arm
ex. Give two coterminal angles for 30
ex. Determine the measures of angles that are
coterminal with 85o for -400o≤ ≤400o
There are infinitely many coterminal angles.