The lines represented by the three equations

 2X+3Y-5=0: 3X-5Y+2=0, and -5X+2Y+3=0

In the adjoining figure ABCD rectangle and, a semi-circle with centre O is inscribed inside the rectangle touching side BC and passing through points A and D, A circle is inscribed inside the rectangle touching the semi-circle and the sides of the rectangle as shown. The ratio of the area of the circle to the area of the semi-circle?

If the radius of a circle is diminished by 10%, then its area is diminished by: