Geometry
Finding a missing leg
Rearranged from the same relation, so it subtracts. The result must be shorter than the hypotenuse.
The Formula
a = sqrt(c^2 - b^2)
Rearranged from the same relation, so it subtracts. The result must be shorter than the hypotenuse.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| c | Known hypotenuse | — | Must exceed the known leg, or the triangle cannot exist. |
What Each Symbol Means
c
Known hypotenuse
Must exceed the known leg, or the triangle cannot exist.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to use the pythagorean theorem page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Use The Pythagorean Theorem, filed under Math. Every number the guide produces comes from substituting into this one line.