1) The document discusses special right triangles, specifically 45-45-90 triangles and 30-60-90 triangles. 2) For 45-45-90 triangles, the hypotenuse is √2 times the length of either leg. For 30-60-90 triangles, the hypotenuse is 2 times the shorter leg and √3 times the longer leg. 3) Examples are provided to demonstrate using the properties of these special right triangles to calculate missing side lengths.