Answer:
3sqrt(2)
Explanation:
The upper triangle is a 30-60-90 triangle. The hypotenuse is twice the length of the small leg.
30-60-90 triangle
hypotenuse = 6
small leg = 3
The small leg of the 30-60-90 triangle is the leg of the lower triangle.
The lower triangle is a 45-45-90 triangle. The hypotenuse is sqrt(2) times the length of the leg.
45-45-90 triangle
leg = 3
hypotenuse = 3sqrt(2)
x is the hypotenuse of the 45-45-90 triangle.
x = 3sqrt(2)