Students explore the concept of similarity and congruence. In this similarity and congruence lesson, students identify and verify whether or not two figures are similar, congruent, or neither. Students use postulates and theorems such as...

Fifth graders explore the importance of triangles in the real world. They find the unknown side of a right triangle using a scale drawing. Students use Pythagoras' Theorem and other appropriate ratios.

Students use wire to make knots and submerse them in pans of detergent to observe how the soap film clings to the wire. They discover this film is called the Seifert Surface. After drawing pictures of the surface, they discuss what...

Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...