An isosceles triangle with sides 13cm,13cm and base of 10cm is inscribed in a circle with radius r.what is the value of 'r'?

• height of triangle = (13^2 - (10/2)^2)^1/2 = 12 cm
  
  area of triangle = abc/4r = (1/2)*base*height
  => 13*13*10/ 4r = 1/2 *10*12
  => r = 169/24 = 7.04
• 10 years agoHelpfull: Yes(23) No(2)
• http://mathhelpforum.com/geometry/187370-proof-isosceles-triangle-inscribed-circle.html
• 10 years agoHelpfull: Yes(3) No(0)
• R = abc/4rs is the formula when triangl inscribes inside a cirlce
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• Is r= 7.01cm??
• 10 years agoHelpfull: Yes(1) No(0)
• 160.24 is the answer among given options.
• 10 years agoHelpfull: Yes(0) No(4)
• The circumradius of an isosceles triangle
  
  a^2/2(a^2-b^2/4)^1/2
  169/2(169-25)^1/2=7.04
  
  
• 10 years agoHelpfull: Yes(0) No(0)
• 0.3 cm?
  r=s/area
• 5 years agoHelpfull: Yes(0) No(0)
• a=13,b=13,c=10
  
  s =(a+b+c)/2 = (13+13+10)/2=18
  
  area of triangle=[s(s-a)(s-b)(s-c)]^1/2
  =[18(18-13)(18-13)(18-10)]^1/2
  = (18*5*5*8)^(1/2)
  =60 cm^2
  
  let r be the radius,then
  r=(a*b*c)/(4*area of triangle)
  
  r=(13*13*10)/(4*60)= 7.04cm
• 5 years agoHelpfull: Yes(0) No(0)