Let \(\mathcal{R}\) be the circle centered at \((0,0)\) with radius \(10.\) The lines \(x=6\) and \(y=5\) divide \(\mathcal{R}\) into four regions \(\mathcal{R}_1, \mathcal{R}_2,\mathcal{R}_3,\mathcal{R}_4\) . Let \([\mathcal{R}_i]\) denote the area of region \(\mathcal{R}_i\). If \([\mathcal{R}_1] > [\mathcal{R}_2] > [\mathcal{R}_3] > [\mathcal{R}_4],\) then find \([\mathcal{R}_1] - [\mathcal{R}_2] - [\mathcal{R}_3] + [\mathcal{R}_4]\).
(I got 84 but that answer is wrong.) :(
Thank you so much for all your help!