Unit Circle Marked At Special Angles Small 320×318 Medium 640×636 Large 1024×1018 Download Tiff Original 3017×3000 | (218.2 KB) Download EPS Vector 355.6 KB Description Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane. All quadrantal angles and angles that have reference angles of 30°, 45°, and 60° are marked from the origin, but no values are given. 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 Unit Circles Source: Florida Center for Instructional Technology Clipart ETC (Tampa: University of South Florida, 2007)