Find the value of x in the isosceles triangle shown below. how do i find x?

To get the value of x you need to use the Pythagorean Theorem 
 
a²+b²=c²  →  3²+b²=6.708204² (√45)
                     9 +b² =45.000001
                    -9   ↓   ↓-9
                   
         zero pair   √b² = √36.000001
                           b = 6
One side of the isosceles the x is 6, but we need the whole part so for last you just multiply 6×2= 12 
The answer is       X=12

Ithink your answer is c mark me brainliest