Answer:
Since you didn't provided any lengths,I used my own so you could see the process of solving this type of a problem.
Step-by-step explanation:
a² + b² = c²
side1² + side2²  = hypotenuse²    side 1 = 1 cm    side 2 = 2 cm
                            solve for the hypotenuse
Hyp  = √(s1² + s2²)
    = √(1² + 2²)
    =  √(1 + 4)
    =  √5
Hyp = 2.235      my right triangle hypotenuse measrured  2.2 cm