AC and BD are two perpendicular diameters of a circle with centre O. If AC = 16 cm, calculate the area and perimeter of the shaded part.

Find the area of circle circumscribing an equilateral triangle of side 15 cm.

The shape of the top of a table in a restaurant is that of a segment of a circle with centre O and ∠BOD = 90°. BO = OD = 60 cm. Find :

(i) the area of the top of the table;

(ii) the perimeter of the table.

In the given figure, ABCD is a square of side 5 cm inscribed in a circle. Find :

(i) the radius of the circle,

(ii) the area of the shaded region.