Answer:
We need to know the known side lengths to answer the question but I'll do my best to help you answer the question.
Explanation:
Square the hypotenuse and subtract the answer by the square of the known leg. The square root of the answer will be the missing leg.
Pythagorean theorem is a²+b²=c² to find the hypotenuse.
But in this case, sense you are trying to find the length of a leg, it is c²-a²=b² (c is the hypotenuse length and a is the known leg length).