Anoop managed to draw 7 circles of equal radii with their centres on the diagonal of a square such that the two extreme circles touch two sides of the square and each middle circle touches two circles on either side. Find the ratio of the radius of the circles to the side of the square.
1) [2+ 7sqrt(2)]:1
2) 1:[2+ 6sqrt(2)]
3) 1:[2+ 7sqrt(2)]
4) 1:(4+ 7sqrt(3)]

• The extreme circles will have radius perpendicular to sides..so the part of diagonal till the centre of cirlce will be sqrt(2)r [Make diagram and it will be clear]..now remaining portion is r , 5 more circles will contribute 10r and last circle will contribute sqrt(2)r + r.
  
  total 12r + 2sqrt(2)r = sqrt(2) side
  
  so ratio of r:s = 1/2+6sqrt(2) .... option b
• 14 years agoHelpfull: Yes(8) No(0)