Equation of a Plane In Normal Form
Three dimensional plane of Class 11
Equation of a plane in normal form
The vector equation of a plane normal to unit vector 
and at a distance d from the origin is 
= d.
If l, m, n are direction cosines of the normal to a given plane which is at a distance p from the origin, then the equation of the plane is lx + my + nz = p.
