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...

Three activities make up a solar system lesson that features the sun, its light, and the shadows it produces. Scholars step outside to discover the changes shadows make at different times of day, take part in a demonstration of...

Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.

Four is the perfect number—if you're talking about parallelograms. Scholars determine a possible fourth vertex of a parallelogram in the coordinate plane given the coordinates of three vertices. They read a conversation...

Describes, with illustrations, the basic two-dimensional shapes students will encounter in elementary Math.