Circles or Pie Diagram:

Circles or pie diagrams are alternative to squares. These are used  for the same purpose i.e. when  the values are differing  widely in their magnitudes. These diagrams are more attractive then circles. Thus pie diagrams are preferred to square diagrams .Both these diagrams involve the same amount of labour. For example taking square roots of the given values and dividing the same by a common factor so as to attain the radii for the circles. 

The area of the circle which represent the given values is calculated by the formula () where () pie =22/7 and r= radius of the circle. The sides for squares are taken as the radii for different circles.