Search "proofs"
Basic triangle proofs module example
Simple worked example of using http://www.khanacademy.org/math/geometry/triangles/e/geometry_proofs_intro
Basic triangle proofs module example 2
Another example of using http://www.khanacademy.org/math/geometry/triangles/e/geometry_proofs_intro
Fill-in-the-blank triangle proofs example 1
Sal works through an example of http://www.khanacademy.org/math/geometry/triangles/e/geometry_proofs_1
Fill-in-the-blank triangle proofs example 2
Worked example for this type of module: http://www.khanacademy.org/math/geometry/triangles/e/geometry_proofs_1
