In the figure given below, ABC is an equilateral triangle of side $8 \mathrm{cm}$. $A, B \text{and} C$ are the centres of circular arcs of equal radius. Find the area of the shaded region correct up to $2$ decimal places. (Take $\mathrm{\pi }=3.142$ and $\sqrt{3}$$=1.732$)

A circle is inscribed in regular hexagon of side $2\sqrt{3 }\mathrm{cm}$. Find 

(i) the circumference of the inscribed circle

(ii) the area of the inscribed circle 

In the figure given below, a chord $AB$ of a circle of radius $10 \mathrm{cm}$subtends a right angle at the centre Find the area of the sector $OACB$and the major segment . Take $\mathrm{\pi }=3.14$