Question 180
On the unit circle with the center at the coordinate origin, we select the circular arc with intersection points $A$ and $B$, which lies in the first quadrant. Let $p_{1}$ be the area of the figure below the circular arc and above the abscissa axis, and let $p_{2}$ be the area of the figure to the left of the circular arc and to the right of the ordinate axis (see figure). Prove that the sum $p_{1}+p_{2}$ depends only on the length of the circular arc, but not on its position.
