Answer:
c ≈ 34.7
Explanation:
if we know two sides of the triangle, we can find the third one using the Pythagorean Theorem.
a² + b² = c²
In this case, we need to find the value of c, which is always the hypotenuse or the longest side. We find the longest side to be AB, since it is opposite the largest angle in the triangle, the right angle.
We substitute the values of a and b in the equation. Note, a and b are interchangeable, but c is NOT!. C must always be the longest side for the formula to work.
25² + 24² = c²
625 + 576 = c²
1201 = c²
c =

c ≈ 34.6554469023
Edit: Since this matches none of the answers, I don't know what went wrong, feel free to report this.