Please help! I need this to pass. If you are trying to get points please just chose a different question and don't mess with mine. I am in a state of trouble and I just need a helping hand.

The answer is 41
Step-by-step explanation:
To solve this we must use the formula a^2+b^2=c^2. if we substitute in the values we get 9^2+40^2=c^2. The first variable is 81, then the b variable is 1600. The hypotenuse is the c value. 81+1600 is 1681, now we must find the square root of 1681. The answer is 41. Tell me if I'm wrong :)