Three circles each of radius 3.5 cm are drawn in such a way that each of them touches the other two. Find the area enclosed between these circles.
The three circles are drawn in such a way that each of them touches the other two.
So, by joining the centers of the three circles, we get,
AB = BC = CA = 2(Radius) = 7 cm
Therefore, triangle ABC is an equilateral triangle with each side 7 cm.
∴ Area of the triangle× a2
where a is the side of the triangle.
= 21.2176 cm2
Now, Central angle of each sector = = 60° (60π/180)
= π/3 radians
Thus, area of each sector = (1/2) r2θ
= (1/2) × (3.5)2 × (π/3)
=
= 6.4167 cm2
Total area of three sectors = 3 × 6.4167 = 19.25 cm2
∴ Area enclosed between three circles = Area of triangle ABC – Area of the three sectors
= 21.2176 – 19.25
= 1.9676 cm2
Hence, the required area enclosed between these circles is 1.967 cm2 (approx.).