1. Similar Right Triangle Theorems Theorem 8.17 – If the altitude is drawn to the hypotenuse if a right triangle, then the two triangles formed are similar to the original triangle and to each other.

2. Geometric Mean If a, x, and b are positive and a = x a = x x b x b Then x is called the geometric mean between a and b. The geometric mean is always positive.

3. Geometric Mean Theorem Theorem 8.16 – If the altitude is drawn to the hypotenuse of a right triangle, then the measure of the altitude is the geometric mean between the measures of the parts of the hypotenuse.