A Triangle's Angles

The sum of the measures of the interior angles of any triangle is 180°.

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

To reflect an object, make sure the "Reflect Object about Line" tool is selected. Then click the object to reflect, followed by the line segment.

Steve Kifowit, Created with GeoGebra