Texas Instruments
Texas Instruments: Geometric Representation of Trig Functions
Using similar triangles, a relationship is established between the six trigonometric functions of an angle and simple line segments. These relationships are then confirmed using line segment measurement capabilities of the graphing...
Purple Math
Purplemath: Basic Trigonometric Ratios: Examples
Demonstrates how to use trig ratios to do simple solving of triangles.
Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Conversion
This site displays the formulas for the simple conversions of degrees to radians and radians to degrees. Near the bottom of the page there are examples of these conversions.