
Hi Rohit
I don't see any need and any way to use MassPoint concept here. It's a very basic question and can be solved very easily with basic geometry concepts.
See in the below diagram, as the points on two mutually perpendicular sides are mid points of those respective sides, we get to know that
(3 + x + 20) + (2 + y) = Half of area of rectangle {as the remaining triangle has same base and height as that of rectangle and hence have half of area of rectangle}
Also, with same logic as above (x + Shaded Area + y) = Half of area of rectangle.
Of course two halves of same area are equal, so equating them we get:
(3 + x + 20) + (2 + y) = (x + Shaded Area + y)
i.e. Shaded Area = 3 + 20 + 2 = 25.
Kamal Lohia
