Nonpolyhedron bounded by a curved surface and a flat base.
Solid bounded by a conical surface and a plane that does not go through the intersection point of the generating lines, called the apex of the cone.
A cone is bounded by a plane surface called its base and a curved surface called its lateral surface. The vertex of a cone is called an apex.
 If the base of a cone is a circle, then the cone is a circular cone.
 If the base of a cone is an ellipse, then the cone is an elliptic cone.
Properties
Classification of Cones  
Right  Oblique  
Cones with a circular base  
Cones with a non‑circular base

Formulas
The formula for the surface area A of a right circular cone is A = πr(r + L), where r is the length of the circle’s radius and L is the slant height.
The formula for the volume V of a right circular cone is V = \(\frac{πr^{2}h}{3}\), where r is the length of the circle’s radius and h is the height of the cone.
Examples
Many everyday objects have the shape of a cone: funnel paper cone cups, icecream cones, Christmas trees, party hats, etc.