Given: Ray DR bisects angle CDA, angle 3 is congruent to angle 1, and angle 4 is congruent to angle 2 Prove: Angle 3 is congruent to angle 4
Tutor.com

Triangle proofs. Questions & Answer keys.
West irondequoit Centeral School District

Given: AC=DC and BC= CE Prove:Tri ABC= TRi DEC
Tutor.com

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

Indepth review of how to write a proof, with examples and definitions along the way.
Proofs

Interactive quiz on properties
Math Warehouse

This provides 4 to 5 congruent triangle proofs for more complex situations.
Analyze Math

This site outlines the theorems about parallelograms with proofs to these theorems.
Steve Wilson of Sonoma State University

Very comprehensive site concerning mathematical proofs. Contains excellent examples and interactive exercises.
Cut The Knot

I need help with problems on right triangles. [ File > http://www.tutor.com/SharedSessionFiles/9e83283f0640454cb7b3807eedd23958_Right_Triangle_Homework.jpeg ]
Tutor.com
