You have to get C^2 And A^2. Then you subtract C^2 and A^2. Then what you get you have to get the square root of that.

Audge

the answer is 40
a common right triangle is a 3-4-5. So any similar multiples of those numbers is also a right triangle. 3 × 10 = 10, 4 × 10 = 40, and 5 × 10 = 50