This lesson focuses on rigid transformations, a specific set of rules that convert one geometric figure into another one. There are many different types of transformations, like reflections or rotations. It provides several practice...

A rigid motion of the plane is a map of the plane to itself which preserves distances between points. The purpose of this task is to use fixed points as a tool for studying and classifying rigid motions of the plane, i.e., translations,...

In this task, seven pennies are placed in a circle so that they are all touching one in the center and their neighbors. Students are asked to find as many rigid motions of the plane as they can which are symmetries of this configuration...

Background image of normal disc-shaped red blood cells from the University of Utah. Inset shows sickled red blood cells, curved and rigid, from the Virginia Medical College.

Given distinct, congruent triangles, students are asked to show that congruence can always be shown with one, two, or three rigid motions. Aligns with G-CO.A.5.

The goal of this task is to use the unit circle and rigid transformations in order to establish some fundamental trigonometric function identities. Aligns with F-TF.A.2 and F-TF.A.4.

Explores how to predict degrees of freedom of a mechanism. Understand that in mechanics degrees of freedom is one of the most important concepts. Video length: 4 min. 41 sec.

This lesson focuses on wallpaper groups. While there are infinitely many possible patterns, they all have one of just 17 different symmetry groups. These are called the Wallpaper Groups. Every wallpaper group is defined by a combination...

In this task, students are shown three unit squares and two line segments connecting two pairs of vertices. They are asked to find the area of a triangle formed by intersecting lines. They can solve it using coordinate geometry or...

All matter is made of atoms! And atoms are made of even smaller more fundamental particles. Atoms are not shiny little rigid spheres as we depict in drawings and simulations; they're more like a squishy storm of tiny particles swirling...

Information about rigid gas permeable (RGP) contact lenses as a treatment for myopia, and children who can wear them.