The document discusses congruent triangles and the different tests that can be used to prove triangles are congruent, including side-side-side (SSS), side-angle-side (SAS), angle-angle-side (AAS), and right angle-hypotenuse-side (RHS). It also provides examples of isosceles, equilateral, and right triangles and defines triangle terminology such as altitude, median, and right bisector.