Pythagorean Theorem is A^2 + B^2 =C^2. So, to find a leg instead of the hypotenuse you switch it around to C^2 - B^2=A^2. 10^2 - 8^2= the missing leg. 100- 64=C^2. 100-64=36. So then, you just square root the 36 which is 6. So 6 is the length of the other leg. And, if you want to you can take original Pythagorean Theorem and plug in all the numbers to double check.
