Trigonometric Ratios of Obtuse Angles

Below shows ∠DAC.

You can shift the point C to change the size of ∠DAC.


Instructions:

1. Adjust the size of ∠DAC.
2. Check the boxes.
3. Observe the values of the trigonometric functions: $\sin \theta$, $\cos \theta$ and $\tan \theta$.
4. Observe the values of the trigonometric functions: $\sin \left( {180^\circ - \theta } \right)$, $\cos \left( {180^\circ - \theta } \right)$ and $\tan \left( {180^\circ - \theta } \right)$.
5. Repeat steps 1 ~ 4 for other sizes of ∠DAC.

Supplementary Angles: Angles that add up to ${180^\circ }$.




Download the GeoGebra file: http://www.geogebratube.org/material/download/format/file/id/44998

Download the GeoGebra Worksheet: http://db.tt/3guaUADv

Download the Worksheet: http://db.tt/6MFfkRFB