Hint:
The little triangle is half of an equilateral triangle.
Use angle sum of a quadrilateral
then
trigonometry.
On the left, we have a 30 - 60 - 90 right triangle
Side of 1 is opposite thw 30 degree angle
So...in a 30-60-90 right triangle, the side opposite the 90 degree angle will be twice as long = 2
The sum of the interior angles of a quadrilateral = 360 degrees
So.....the missing angle , A, at the top right can be found as
90 + 90 + (60 + 90) + A =360
330 + A = 360
A = 360 - 330 = 30°
And the triangle on the right is also a 30-60-90 right triangle
The side of 2 is opposite the 30 degree angle.....and x is opposite the 90 degree angle...so...as before....
x = 2 * 2 = 4