Since the two smaller sides of the right triangle are 3 and 4, so the hypotenuse must have length 5.
Since in a right triangle, the longer side is hypotenuse and other two sides are base and perpendicular.
Let base = 3, perpendicular = 4 we have to find hypotenuse.
By using Pythagoras theorem, which states






So, the given argument is correct that the two smaller sides of the right triangle are 3 and 4, so the hypotenuse must have length 5.