Answer: 85
Work Shown:
![a^2 + b^2 = c^2\\\\40^2 + 75^2 = c^2\\\\1600 + 5625 = c^2\\\\7225 = c^2\\\\c^2 = 7225\\\\c = √(7225)\\\\c = 85\\\\](https://img.qammunity.org/2023/formulas/mathematics/high-school/mq6mhxp6stps9ju4myqwnd73d7leqzz0sk.png)
I used the pythagorean theorem with a = 40 and b = 75. The order of the 'a' and b doesn't matter, as long as c is the largest side.
The 40-75-85 pythagorean triple is the scaled up version of the 8-15-17 triple (multiply each piece by 5).