Classifying Sides of a Right Triangle

Date: 06/12/2002 at 21:00:34
From: Stephanie
Subject: trig

How do you find the adjacent, hypotenuse, and opposite sides on a 
triangle?

Date: 06/13/2002 at 05:40:14
From: Doctor Jeremiah
Subject: Re: trig

Hi Stephanie,

The opposite side, adjacent side, and hypotenuse are names of sides
only for triangles with a right (i.e., 90 degree) angle.  If the
triangle doesn't have a right angle then the sides cannot use those
names.

The hypotenuse is the longest side.  It is ALWAYS the longest side.

The adjacent and opposite sides are relative to whichever angle
you are trying to use.  The adjacent side is beside the angle
you are trying to use and the opposite side is across the triangle
from that angle.

For example, say you are trying to use angle "a"

        +
        |\
        | \
        |  \
        |   \
        |    \
        |    hypotenuse
        |   (longest side)
        |       \
     opposite    \
 (across from a)  \
        |          \
        |         a \
        +------------+
           adjacent
          (beside a)

Let me know if this doesn't completely answer your question
or if I can help with a different question.

- Doctor Jeremiah, The Math Forum
  http://mathforum.org/dr.math/