Answer:
It depends on what's given in the problem.
Explanation:
There's a few ways to find the hypotenuse of a triangle, but we must have something given to us.
A Few Methods (Most Common to Least Common):
The Pythagorean Theorem. 2 legs of a right triangle are given. You should add the 2 legs together to find the hypotenuse.

Sine, or Cosine. This is only used when there's a given angle, and/or at least one given side.


Rare, but possibly we need to find the area of the triangle. There needs to be at least 1 angle given.
This is the formula we need to find the Hypotenuse:

This is a lot to learn. Let me know if you have any questions.