Interior and Exterior of a Quadrilateral

Interior Points:

Points that lie inside the quadrilateral (P and M in the diagram)

These points are completely enclosed by the quadrilateral's boundaries There are infinitely many interior points

In the diagram, shown in red

Exterior Points:

Points that lie outside the quadrilateral (L, O, and Q in the diagram)

These points are not enclosed by the quadrilateral There are infinitely many exterior points

Points on the Quadrilateral:

Points that lie on the boundary/perimeter (N, A, B, C, and D) These points are neither interior nor exterior They form the boundary of the quadrilateral