Very simply, geometers examine a pair of rectangles on graph paper and find a translation and rotation to demonstrate their congruence. A couple of questions follow to stimulate critical thinking about other possibilities.

While it may seem incredibly obvious to the geometry student that congruent sides make congruent triangles, the proving of this by definition actually takes a bit of work. This exercise steps the class through this kind of proof by...

After learning that the sum of interior angles for triangles is 108 degrees, take it further to show that the sum of angles in any polygon is the same! Using hexagons, pupils practice finding the measure of the six congruent angles. Make...

This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...

Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.

Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...

Students, teachers, and parents alike will enjoy this challenging math site. It contains a clever brain teaser section plus creative problems related to algebra, geometry, measurement, numbers, statistics, and probability. A Spanish...

The resource investigates congruent shapes. Examples and definitions are included.

Students learn about transformations. Topics explored are resizing, types of transformations, and congruent shapes. Examples and definitions are included.

[Free Registration/Login Required] Students will move the vertices of the quadrilateral to form the congruent quadrilateral. Click learn more to watch a video and click challenge me to answer a practice question.

This site from The Math Forum is a great site if you are looking for activities to engage your students in learning about line symmetry. Peruse this collection of activities for one or two or four that would be right for your students....