Isosceles and right-angled

In the figure below there are three congurent, isosceles right-angled triangles, numbered with three Fibonacci numbers (as it is shown).

We inscribed a circle to the first one, and two different squares to the last two. If the largest area's number is $x$ , and the smallest area's number is $y$ , then find the value of $x-y$ .

For example: If you think that the largest area is the red, and the smallest is the blue, then your answer is $2-3=-1$ .

Note : All of the three areas are different.