Answer:
It is A
Explanation:
The pythag theorem states that for a right triangle, a^(2+)b^(2)=c^(2)
this triangle can be divided into two right triangles, and to find the base (x), flip one half of the triangle on it's side and apply the theorem. The equation is a^(2+)8^(2)=10^(2), which leaves A as 6 if you solve the equation right, then you add 6 + 6 because you found the value of one of the triangle's base. (I'm not the best at explaining things.)