Three circle of radius 3.5 cm are placed in such a way that each circle touches the other two. The area of the portion enclosed by the circles is :

Answer: Option A

Required area = (Area of an equilateral Δ of side 7 cm) - (3 × Area of sector with θ = 60° and r = 3.5 cm)
$$=\left[\left(\frac{\sqrt{3}}{4}\times 7\times 7\right)-\left(3\times \frac{22}{7}\times 3.5\times 3.5\times \frac{60}{360}\right)\right]c{m}^2$$
$$\begin{array}{rl}& =\left(\frac{49\sqrt{3}}{4}-11\times 0.5\times 3.5\right)c{m}^2\\ & =(21.217-19.25)c{m}^2\\ & =1.967c{m}^2\end{array}$$