Because it has a curved surface it is not a polyhedron.

And for reference:

Surface Area of Base = π × r^{2}

Surface Area of Side = π × r × s

or

Surface Area of Side = π × r × √(r^{2}+h^{2})

Volume = π × r^{2 }× (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. If you cannot see the animation at all, you will need to install "Flash Player".

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

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 × r^{2 }× h

The volume of a cone is:

π × r^{2 }× (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!