The Math Forum: Angles of an Octahedron

Three geometric constructions students like to say are "impossible" are explained here. Trisecting an angle, squaring a circle, and doubling a cube are examined as being either possible or impossible, depending on the "rules" you use.

Putt-Putt golf can be a great tool in helping students understand angles and their reflections. Here a teacher demonstrates the "Course," set up in his classroom to assist in explaining to students how to use geometry and angles in...

This page brings you to a table of contents of three-dimensional figures. Selecting a figure will bring you to a page defining and illustrating the figure with applicable formulas listed.

Dr. Math at the Math Forum offers a way of remembering alternate exterior and alternate interior angles by looking at the words and realize what they say and apply it to the picture.

Q and A Math Forum site that answers the question of "How do I measure angles using a protractor?"

This is a lesson plan of paper folding as a method of proof. A Java applet version of the activity can be accessed, giving the actual lengths and angle sizes.

This question and answer site is about finding the area of a cone when the height and the angle at the convergence point are given. The site goes on to explain how a cone relates to a circle.

This site contains a wealth of problems that deal with the basic definitions of medians, altitudes, angle bisectors, and perpendicular bisectors or the defining characteristics of the different types of triangles. There are also...

This site not only defines what a polyhedron is, but it allows you to view each of the five regular polyhedra through an interactive exercise. After selecting which polyhedron you'd like to see, it will tell you its name and how many...

Contains six examples of polyhedra nets (cube, tetrahedron, octahedron, dodecahedron, icosahedron, cubosctahedron).