Using the pythagorean theorem, the value of x would be eight. The equation of Pythagorean is
a^2 + b^2 = c^2
(C is the hypotenuse. Hypotenuse being the length of 10) Applying the lengths leaves us with the equation
36 + x^2 = 100.
You then subtract 36 from 100 to get X alone on the opposite side of the equation.
X^2 = 64
Lastly, you take the square root of 64. Therefore, the final answer will be eight.