# Unit Circle Labeled At Special Angles

## Description

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with the x- and y-axes indicated. All quadrantal angles and angles that have reference angles of 30°, 45°, and 60° are given in radian measure in terms of pi. At each quadrantal angle, the coordinates are given. These coordinates can be used to find the six trigonometric values/ratios. The x-coordinate is the value of cosine at the given angle and the y-coordinate is the value of sine. From those ratios, the other 4 trigonometric values can be calculated.

## Keywords

45°, analytic geometry, circles, coordinate plane, cos, cosecant, cosine, cot, cotangent, csc, Degree, degrees, quadrantal angles, quadrants, radian, radians, radius of 1, ratio, sec, secant, sin, Sine, special angles, Tan, tangent, trig, trig ratios, trigonometric functions, trigonometry, unit circle

## Galleries

## Source:

Florida Center for Instructional Technology *Clipart ETC* (Tampa: University of South Florida, 2007)