Investigating Sine, Cosine, Tangent

1. Move point D along the quarter circle. Describe how the triangle changes.

2. Move point B along the x-axis. Describe how the triangle changes.

3. Click the checkbox to show sin α. Describe how sin α is related to the triangle. Test your conjecture on triangles of different shapes and sizes.

4. Click the checkbox to show cos α. Describe how cos α is related to the triangle. Test your conjecture on triangles of different shapes and sizes.

5. Click the checkbox to show tan α.  Describe how tan α is related to the triangle. Test your conjecture on triangles of different shapes and sizes.

Adapted from Jackie Doyle, University of Pittsburgh, Created with GeoGebra