Question

HELP!!!
Why are some right triangles called special right triangles?

Answer 1

Because these right triangles are meant for specific purposes in geometric formula's.
There are right triangle's called "angle-based" triangles. This type of triangle can form various relationship's which turn out simplier than they seem.
For example, 45°–45°–90°.
The angle based right triangle it is called.
Maybe another form of a special right triangle is a "side-based" right triangle. This is one in which the lengths of the sides form ratios of whole numbers, such as 3 : 4 : 5, or of other special numbers such as the golden ratio.
The purpose of special right triangles are meant to make geometric equations simpler without having to complicate them.