An example of a plane geometric surface is the

A. side of a cylinder.

B. surface of a sphere.

C. side of a cone.

D. side of a box.

In geometry, a plane is a flat surface without thickness. It only has a length and a width or an x and a y.

An example of a plane geometric surface is the D. Side of a box.

Side of a cylinder, surface of a sphere, side of a cone are not examples of a plane geometric surface. These sides are round and not flat.