not according to the software

I also answered s=square root of 3 but according to the software the answer is s=1. I think we both assumed the larger triangle was being bisected evenly.

I worked the problem using pythagoreon's thrm and the sides of the right triangle in the negative quadrant to find the length of the radius =2. Then the larger equilateral triangle has sides 2,2, 2 times square root 2 applying the knowledge that the ratio of a right equilateral triangle is 1:1:square root 2. Then S = (2 times square root 2) - (square root 3).

Thats where I am stuck. How do I get from subtracting these two square roots to the answer 1? Is there a simpler approach.