difference b/w the perimeters of two concentric circles is 66.find the difference b/w radius

• R=10.5+r
  
  2*pie*(R-r)=66
  R-r=10.5
  
  
• 12 years agoHelpfull: Yes(11) No(1)
• 10.5
  (2pi)*R-(2pi)*r=66
  R-r=66/(2*pi)=10.5,where pi=22/7
• 12 years agoHelpfull: Yes(8) No(1)
• ANS : 10.5 approx.
  If R and r are the radii of the 2 concentric circles (larger and smaller resp),
  difference b/w the perimeters = 2*pi*R - 2*pi*r = 2*pi*(R-r) = 66;
  Therefore difference b/w their radii = R-r = 66/(2*pi) = 10.504 approx.
  as pi is only approximately equal to 22/7.
• 12 years agoHelpfull: Yes(5) No(0)
• here 2*22/7(r1-r2)=66
  then r1-r2=21/2
  =10.5
• 12 years agoHelpfull: Yes(0) No(0)
• 21/2
  2*3.14(R-r)=66
• 11 years agoHelpfull: Yes(0) No(0)
• R-r=66/2pi
• 11 years agoHelpfull: Yes(0) No(0)
• 66/(2*pi)
  
• 10 years agoHelpfull: Yes(0) No(0)
• 2*pi*(R-r)=66
  (R-r)=10.504
• 4 years agoHelpfull: Yes(0) No(0)