A half-plane is a planar region consisting of all points on one side of an infinite straight line, and no points on the other side. If the points on the line are included, then it is called an closed half-plane. If the points on the line are not included, then it is called an open half-plane.

What do you mean by half plane?

: the part of a plane on one side of an indefinitely extended straight line drawn in the plane.

How do you find the half plane inequality?

If the inequality is a “≤”or “≥”, then the graph will be a closed half‐plane. A closed half‐plane includes the boundary line and is graphed using a solid line and shading.