Answer:
The shape is a square and a triangle, so all sides of the square are equal to 6, and applying the Pythagorean law to a right-angled triangle, we can find the value of x
Then
[tex] {x}^{2} = {6}^{2} + {3 }^{2} \\ {x}^{2} = 36 + 9 \\ {x}^{2} = 45 \\ x = 3 \sqrt{5} [/tex]
