Q8 of 68 Page 15

Four equal circles, each of radius a, touch each other. Show that the area between them is.

Radius of each circle = a meter


If we join the centre of each circle it makes a square of side = 2a


Area of square = (2a)2 = 4a2m2


Area of each quadrant of circle =


Area of 4 quadrants =


So,


Area between circles = 4a2 – πa2



More from this chapter

All 68 →
5

Four equal circles, each of radius 5cm, touch each other as showing fig.15.65. Find the area included between them.


 6

Four cows are tethered at four corners of a square plot of side 50m, so that they just cannot reach one another. What area will be left un-grazed?

 9

A square water tank has its side equal to 40m. There are four semi-circular grassy plots all round it. Find the cost of surfing the plot at Rs.1.25 per square meter.

 10

A rectangular park is 100m by 50m. It is surrounded by semi-circular flower bed sall round. Find the cost of leveling the semi-circular flower bed sall 60paise per square meter.