There are various forms for the equation of a plane. You may already be familiar with the parametric form. Here I discuss the scalar product forms. This is a very useful and common form of the plane.

The form r.n=D

Planes - Scalar Product Form r.n=D : ExamSolutions Maths Revision - youtube Video

The form (r-a).n=0

Equation of a plane in the form (r-a).n=0 : ExamSolutions Maths Revision - youtube Video