(a) In the figure (i) given below, the boundary of the shaded region in the given diagram consists of four
semicircular arcs, the smallest two being equal. If the diameter of the largest is 14 cm and of the smallest is
3.5 cm, calculate
(i) the length of the boundary.
(ii) the area of the shaded region.

(b) In the figure (ii) given below, a piece of cardboard, in the shape of a trapezium ABCD, AB || CD and
∠BOD = 90^{\circ} , quarter circle BFEC is removed. Given AB = BC = 3.5 cm and DE = 2 cm. Calculate the area
of the remaining piece of the cardboard.