A helpful scientific calculator that runs in your web browser window.
Holt Online Learning

Practice using Pythagorean Theorem to solve for the third side of a right triangle. Answers included.
Math.com

All about triangles.
Tim's Triangular Page

A page with links for properties of circles and different types of polygons. Each link has great visuals with clear markings, definitions, and formulas.
Cool Math

Definition and picture of a 3:4:5 triangle. Gives other examples of pythagorean triplets.
Math Open Reference

Definition of a 454590 triangle and the ratio of its sides. Includes a great picture.
Math Open Reference

Definition of a 306090 triangle along with the ratio of its sides.
Math Open Reference

Calculate the perimeter and area for each triangle. Answers included.
MathDrills.com

The worksheets below can be used as part of extra math homework. These geometry worksheets are free and easily printable. They cover typical school work from grade 4 through 8. They include questions on polygons, 3D objects, angles, and calculations of area, volume, etc.
Helping With Math.com

In this Early Edge video lesson, you'll learn more about Triangles, so you can be successful when you take on highschool Math & Geometry.
The Princeton Review
