The Pythagorean theorem is what we are using, adapting it to find the leg.
The Pythagorean theorem is:
A2+B2=C2
If you have the legs, then that will find you the hypotenuse.
If you need to find a leg and you have a leg and the hypotenuse, then either:
A2=C2-B2
or
B2=C2-A2
The legs can be...