1.
Let S1={zC:z5}S_1 = \{z \in \mathbb{C} : |z| \le 5\}, S2={zC:Im ⁣(z+i13i)>0}S_2 = \left\{z \in \mathbb{C} : \mathrm{Im}\!\left(\dfrac{z + i}{1 - \sqrt{3}\,i}\right) > 0\right\}, and S3={zC:Re(z)>0}S_3 = \{z \in \mathbb{C} : \mathrm{Re}(z) > 0\}. Then the area of the region S1S2S3S_1 \cap S_2 \cap S_3 is: