In Chapters 7 and 8,you found the unknown sides of a triangle using
proportions and the known sides of similar and congruent triangles. To
find an unknown side of a single right triangle, you will need to use the
Pythagorean theorem.
The Pythagorean theorem is a special equation that defines the relation-
ship between the sides of right triangles. In order to use it successfully, you
must first learn the standard way to label the sides of right triangles. In a right
triangle, the two sides that form the right angle are referred to as the legs. It
is standard for the legs of a right triangle to be called aand b. The longest side
(which is always opposite the right angle), is called the hypotenuseand it is
standard for the hypotenuse to be called c. The correct standard labeling of
a right triangle is shown in the following illustration:
abc