After each section there is an optional (though highly recommended) quiz that you can take to see if you've fully mastered the concepts. Don't forget to visit the message board and the formula database.
Follow any of the links below to go to the section you need help with.
Congruent Right Triangles
Isosceles and Equilateral Triangles
Area and volume of solids
For all you computer nerds out there, we've included a section full of short QBasic programs that do basic geometry problems. Feel free to download them, use them, and improve them (they're freeware)!