Answer:
3. 74
Step-by-step explanation:
The pythagorean theorem states that A^2 + B^2 = C^2 (with c being the hypotenuse). So to figure it out we can substitute into the equation.
5^2 = 25
7^2 = 49
25 + 49 = 74
So it would be the square root of 79. I hope this helps! :)