Proves that if the orthocenter and centroid are the same point in a triangle then the triangle is a right triangle. [6:25]

Demonstrates solutions to problems #4-6 of California Geometry released state test questions. Problems address understanding of proof by contradiction and proving triangles congruent. [11:56]

In this video tutorial [7:28], the instructor shows how to determine if two triangles are congruent using different triangle congruence postulates: SSS, SAS, ASA, AAS. Practice problems available.

Demonstrates solutions to problems #17-20 of California Geometry released state test questions. Problems address understanding of similar triangles, parallelograms and properties of the diagonals of parallelograms. [11:11]

In this video tutorial [13:28], the instructor identifies the different triangle congruency postulates: SSS, SAS, ASA, AAS. Practice problems available.

Explains using multiple proofs that a point on a perpendicular bisector is equidistant from the endpoints of the segment it bisects. Proofs use triangle congruency postulates. Lays the foundation for understanding the circumcenter of a...

This video uses the SSS, ASA, SAS, and AAS postulates to find congruent triangles.