## Sunday, August 5, 2012

### Angle Sum Theorem

Move points A, B, and C to choose the triangle size and shape you want.  Move sliders $\alpha$ and $\beta$ to the extremer right

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com
By Guillermo Bautista Jr. , Created with GeoGebra

1. What do you observe about angles t, u and v
2. What is the sum of  v, u, and t? Justify your answer.
3. Based on your observations above, what can you say about the sum of the interior angles of a triangle? Explain your answer.
Snapshot