Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...

In this geometry worksheet, students identify the interior and exterior angles using the angle sum theorem. They identify and solve quadrilaterals using properties of quadrilaterals. There are 12 questions with an answer key.

Students may use this computer applet to explore angle sums of triangle, quadrilaterals, pentagons and hexagons.