Sunday, December 2, 2012

The Inscribed Angle Theorem

In the figure below, angle BAC is an inscirbed angle and angle BOC is the central angle of circle O. Both angles are subtended by the same arc. Make a conjecture about these two angles.
This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to
Check the Show/Hide Angle Measures check box and move any of the points. Is your conjecture always correct? Prove your conjecture.