This activity is used to discover that the sum of the measures of the triangle angles is constant and to discover ways of proving the theorem listed in the activity.

Find missing angles and lengths in inscribed shapes. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Test your mathematical aptitude with challenge exploring the concepts of measurement and geometry. Find the area of the windshield wipers to figure out who sees better in the rain, car drivers or truck drivers. An activity from the NCTM...

Quadrilaterals-parallelograms, rectangles, and trapezoids-are thoroughly introduced in this lesson plan for upper elementary and middle school students. Lots of resources are linked to it to help support the teacher and students....