A right circular cone has height H and radius R. A small cone is cut off at the top by a plane parallel to the base. At what height above the base the section has been made?

Statement (I): H = 20 cm
Statement (II): Volume of small cone: volume of large cone : 1:15

• 20 - (20/3)^(1/3)
  if radius and height of small cone is r and h
  then
  (1/3)*3.14*r^2*h = (1/15)(1/3)*3.14*R^2*h
  r^2*h = (1/15)*3.14*R^2*h .................1
  and by symmetry of triangle in small and large cone
  h/r = H/R .................2
  by solving 1 and 2 and putting H = 10
  h= (20/3)^(1/3)
  height above the base section
  = 10 - (20/3)^(1/3)
• 9 years agoHelpfull: Yes(0) No(0)