Answer:
5 units
Explanation:
To find a missing side of a right triangle you can use the Pythagorean theorem which is a^2+b^2=c^2, where c is the hypotenuse. To solve plug in the information we know.
3^2+4^2=c^2, then simplify
9+16=c^2
25=c^2, finally square root both sides of the equation.
5=c. So 5 is your answer.