Lessons on Perimeter and Area of Polygons from Math Goodies Discusses the perimeter of polygons, area of trapezoids, and challenge exercises. Available on CD only are the area of triangles and parallegrams, as well as practice exercises with solutions.
Polygons Discusses the differences between the different types of these straight sided figures. Also, explains the difference between regular and irregular shapes.
Pythagorean Theorem A collection of 43 proofs - some interactive - of the Pythagorean theorem.
Tim's Triangular Page Explains the basic properties, formulas, theorems and different types of triangles. Includes proofs and illustrations.
