2. See attachment: There are 2 trapezoids in red, 2 trapezoids in blue, 2 trapezoids in green.
3. Take the red trapezoids (that's the simplest case!):
Point A must be situated on a parallel to the x-axis with the equation y = 8.
The area of a trapezoid is calculated by :
So you have to solve for :
So you get 2 different points A: or
4. The next 4 trapezoids are much more difficult to determine.