What is the value of x?

3sqrt(2)

Step-by-step 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)