The adjoining figure shows a set of concentric squares. If the diagonal of the innermost square is 2 units, and if the distance between corresponding corners of any two successive squares is 1 unit, find the difference between the areas of the eighth and seventh squares, counting from the innermost square.
AB is the diameter of the given circle, while points C and D lie on the circumference as shown. If AB is 15 cm, AC is 12 cm and BD is 9 cm, find the area of the quadrilateral ACBD.
In the adjoining figure, points A, B, C and D lie on the circle. $AD = 24$ and $BC = 12$. What is the ratio of the area of $\triangle CBE$ to that of $\triangle ADE$?