The two legs of a right triangle are 9 and 40. how long is the third side

Refer to the diagram shown below.

Let x = the length of the third side (the hypotenuse) of the right triangle.
From the Pythagorean Theorem, obtain
x² = 9² + 40² = 81 + 1600 = 1681
x = 41

 41

Number nine is f(x)= 40x : ) hoped i ya