Find the lenght x in each triangle. Express your answer in simplified radical form.?

Question

The top is 10, the side is x, and the bottom is 8.

Answer 1

6
6= sqrt(10^2-8^2) = sqrt(36) = 6

Answer 2

Is this a right triangle? Is 10 the length of the hypotenuse (the side opposite the right angle) and 8 the length of a leg?

If so then x² + 8² = 10²

x² + 64 = 100

x² = 100 - 64

x² = 36

x = 6

If it is not a right triangle, then all I can tell you is that
the length of x is between 2 and 18.
2 = 10 - 8, the difference of the given sides
18 = 10 + 8, the sum of the given sides