Point

A point is an exact position or location on a plane surface. It is important to understand that a point is not a thing, but a place. We indicate the position of a point by placing a dot with a pencil. This dot may have a diameter of, say, 0.2mm, but a point has no size. No matter how far you zoomed in, it would still have no width. Since a point is a place, not a thing, it has no dimensions.

Points are usually named by using an upper-case single letter. In the figure above, the points P,Q and R are shown. In this web site, points are shown either as a black dot or with a somewhat larger orange halo. This indicates the point can be dragged with a mouse.

• If a set of points all lie in a straight line, they are called 'collinear'. See Collinear definition
• If a set of points all lie on the same plane, they are called 'coplanar'. Coplanar definition

Dragging hints

1. Move the mouse over a point with an orange halo until a + or a hand symbol appears.
2. Press and hold the mouse button.
3. With the button down, move the mouse. The point will move.
4. Release the mouse button.

Coordinate Geometry

In another branch of mathematics called coordinate geometry, points are located on the plane using their coordinates - two numbers that show where the point is positioned with respect to two number line "axes" at right angles to each other.

For more on this, see

• Introduction to Coordinate Geometry
• Coordinates of a point

Other point topics

• Point
• Plane
• Collinear points
• Equidistant points
• Intersection
• Vertex
• Midpoint
• Locus