Finding the third angle of a triangle becomes easier by the explanation and examples presented.

An interactive site that instructs and demonstrates how to find the fourth angle of a quadrilateral. This site also has many links to other interactive lessons.

In this instructional activity, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles....

This site contains a lesson plan for high school age students. The objective is to discover the factor of proportionality in similar polygons and to relate this factor to the perimeters and areas of similar polygons.

[Free Registration/Login may be required to access all resource tools.] In this tutorial, students recognize congruence and find unknown measures of angles. They can examine guided notes, review guided practice, watch instructional...

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.

Practice using your graphing calculator for Geometry problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.

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...

Explore and measure a variety of quadrilaterals.