IN THE FOLLOWING FIGURE, AB IS THE DIAMETER OF A CIRCLE WITH CENTR...

7. In the following figure, AB is the diameter of a circle with centre O. Point D is on the circle. In the trapezoid ABCD, i) line segments AB and DC are both perpendicular to BC, and ii) AB=2CD. Arc DMB is part of a circle with centre C. What is the ratio between the area of the shaded part and the area of the circle?