Squared off

First, we need to notice finding the green area is enough because it is $\frac {G}{100}\times 100$ = G. so, finding the area is enough. first, area of B+G = 100, because sliding the two green segments down, we get the same square. Therefore, $B + G = 100$ , so $G = 100 - B$ so find the blue area. as I hinted, draw lines to form a triangle and two cutoffs of a circle. Assuming area of triangle as T and cutoffs as C, $T = \frac {10 \times10}{2} = 50$ . but C is a little trickier. since S = 10,the radius of the arcs r is as follows. $d = 10\times \sqrt{2}$ , so we say $r = 5\times \sqrt{2}$ . since all arcs are similar, area of bottom left arc= $\frac{1}{4}\pi r^{2}$ $\approx 39.3$ . so, Area of 1 blue cutoff = $(5\sqrt{2})^{2} = 50 - 39.3$ = 10.7. multiplying by 2 you get 21.4. Therefore finally, B = 50 + 21.4 = 71.4. Substituting that in, we get 71.4 + G = 100, so $G \approx 28.5$