Mathematics
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.

Related Questions
In the given figure, the area enclosed between two concentric circles is 808.5 cm2. The circumference of the outer circle is 242 cm. Calculate :
(i) the radius of the inner circle,
(ii) the width of the ring.

AC and BD are two perpendicular diameters of a circle ABCD. Given that the area of the shaded portion is 308 cm2, calculate :
(i) the length of AC; and
(ii) the circumference of the circle.

Find the area of circle circumscribing an equilateral triangle of side 15 cm.
Find the area of a circle inscribed in an equilateral triangle of side 18 cm.