Answer:
If you need to find the hypotenuse, then square the two sides and add them together then square root that answer to get the hypotenuse. If you need to find a side then take the hypotenuse and other side and square them then subtract the side by the hypotenuse and then square root that answer.
Explanation:
legs; a b hypotenuse c
a^2 + b^2 = c^2 then square root this answer
c^2 - b^2 = a^2 then square root this answer
c^2 - a^2 = b^2 then square root this answer