For this case, the first thing you should do is apply the Pythagorean theorem:
c = root ((a) ^ 2 + (b) ^ 2)
Where,
a, b: sides of the triangle
c: hypotenuse
Substituting values we have:
c = root ((10) ^ 2 + (10) ^ 2)
c = root (100 + 100)
c = root (200)
c = root (2 * 100)
c = 10 * root (2)
Answer
The hypotenuse is:
c = 10 * root (2) inches
