Annenberg Foundation
Geometry 3D Shapes: Euler's Theorem
How do you get a theorem named after you? Euler knows what it takes! The third lesson of five asks pupils to use an interactive activity to compare the faces, vertices, and edges of seven different three-dimensional solids. They use...
University of Regina (Canada)
University of Regina: Math Central: Lesson: Mr. Z's 5 Minute Game of Geometric Pandemonium
Students make a series of geometric drawings of points, obtuse angles, rays, polygons, and the like. Each child is given one but not allowed to show anyone else. The drawing is then taped to the back of the child in front of them. The...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Characteristics of an Orthocenter
Here at The Math Forum, Dr. Math offers interesting properties of orthocenters. Links are provided at the bottom of the page for information on associated topics.
PBS
Pbs Learning Media: Finding the Intersection
In this Cyberchase video, Inez and Digit identify the location of the transformatron using their knowledge of parallel and intersecting lines.
PBS
Pbs Learning Media: Two Points Determine a Line
In this video segment [2:10] from Cyberchase, Digit must make a straight line between the two points and then follow the path created.
PBS
Pbs Learning Media: Two Sightings, Different Information
Jackie and Matt are looking at the same object along two different lines, in this video segment from Cyberchase.