Triangle on the right is 45 45 90 right triangle
Ratio of leg : hypo = a :a√2
Given hypo = 6 so leg = 3√2
As you know leg of triangle on the right is the hypo of the triangle on the left
Triangle on the left is 30 60 90 right triangle
Ratio of short leg :hypo = a : 2a
You know hypo = 3√2 so leg x = (3√2 ) / 2 = 3√2 / 2
Answer is A. 3√2 / 2