This document provides a visual of the unit circle, which is divided into 4 quadrants labeled I, II, III, and IV. The unit circle shows the standard position for measuring angles in radians, with the initial side of the angle laying on the positive x-axis and angles measured counterclockwise from this position. Several example angles are given in radians.

1. Unit Circle / Circular Functions
y
II I
(- , +) (+, +)
terminal r
arm/ side
initial arm/ side
x
III IV
(- , -) (+ , -)
Standard Position of
Initial arm lays
on the x-axis
the origin

2. o
-270o
o o
180o -180o
o
-90o
Sketch:
= 135o
= - 45o
c) = 315o
= - 225o
= 405o
f) = 60o
= - 300o