High School Geometry/Points, Lines, and Planes
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Three of the most basic objects in geometry are the point, the line, and the plane. These are described in the table below.
| Image | Object | Description |
|---|---|---|
 |
Point | A specific place in space. They are infinitely small (they have no size) and are denoted by a single capital letter, in this case, A. |
 |
Line | A straight path that extends infinitely in both directions. Lines are denoted by two points on the line under a line symbol, <->. Also, they are made up of an infinite number of points. |
 |
Plane | A flat surface that extends infinitely in all directions. Planes have no thickness whatsoever and can be made using a minimum of three points. Shown here is a plane being intersected by two lines. Planes are named by four points on the plane (i.e. "plane ABCD"). |
