Question

Four equal circles, each of radius 5 cm, touch each other, as shown in the figure. Find the area included between them.

[ Take $\pi =\mathrm{3.14.}$]

Answer 1

Consider the attached diagram,
the square formed as such is if side 2a
hence area
= area of square - 4× area of a circle quadrant
= (2a)² - 4×πa²/4 = 4a² - $\frac{22}{7}{a}^2=[4-\frac{22}{7}]a^2=\frac{28-22}{7}{a}^2=\frac{6}{7}{a}^2$

here a=5