Answer:
8
Explanation:
This is a right triangle, which fits the Pythagorean Theorem, a^2 +b^2 = c^2. The variables a, b, and c all are sides of the triangle, while a and b are the two legs and c is the hypothenuse.
In this problem, we see that 6 and x are the legs and 10 is the hypothenuse. We put 6 as "a" and x as "b" (but it doesn't matter which is a and b) and 10 is c. Therefore, we have the equation:
6^2 + x^2 = 10^2
which further simplifies to:
36 + x^2 = 100
x^2 = 64
and so x would equal 8 (or -8, but it is impossible to have a side length of -8).
Therefore, the missing side is 8.