Friday, July 29, 2011

Triangle Angle Sum Proof 2

1.) Move the vertices of the triangle to determine the shape and size of the triangle you want.
2.) Move the slider to the extreme right. What do you observe?
3.) What is the relationship between the three angles which meet at a point, and the three interior angles of a triangle?
4.) What can you say about the angle sum of the parallelograms/trapezium formed?
5.) Make a conjecture about your observation.

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)

Another demonstration that shows that the sum of the interior angle of a triangle is 180°.

1 comment:

  1. Eng/ Ahmed elsamin
    New method about general angle division and angle trisection on a links​th/node/1726​th/node/1723

    Discovered By
    Eng/ Ahmed elsamin
    (Arab Republic of Egypt)