Cone

Cone Facts
Notice these interesting things:
  It has a flat base
  It has one curved side
  Because it has a curved surface it is not a polyhedron.
   
And for reference:
  Surface Area of Base = π × r2
  Surface Area of Side = π × r × s
or Surface Area of Side = π × r × √(r2+h2)
   
  Volume = π × r2 × (h/3)

Instructions: In "spin" mode it freely spins and will respond to your mouse. In "drag" mode it stops spinning and you can use your mouse to move it.
   

brass cone
  • The pointy end of a cone is called the vertex or apex
  • The flat part is the base
  • An object shaped like a cone is said to be conical
cone vertex and base

 

A Cone is a Rotated Triangle

A cone is made by rotating a triangle!

The triangle has to be a right-angled triangle, and it gets rotated around one of its two short sides.

The side it rotates around is the axis of the cone.

Volume of a Cone vs Cylinder

The volume formulas for cones and cylinders are very similar:

The volume of a cylinder is: π × r2 × h
The volume of a cone is: π × r2 × (h/3)

So, the only difference is that a cone's volume is one third (1/3) of a cylinder's.

So, in future, order your ice creams in cylinders, not cones, you get 3 times more!

Different Shaped Cones