Undefined terms in geometry points , line & plane

• Points - It has no length, width, or thickness
• Line - It has no thickness but it's length extends indefinitely to both directions
• Plane - It has no thickness and extends indefinitely in all direction
• Collinear - two or more points that lie on the same line
• Non-collinear - Points that do not follow a straight array
• Intersecting lines - are lines that intersect.

  The common point between two lines is

  called the point of intersection.
• ray - part of a line that continues on

  one side. There is only one endpoint.
• line segment - consists of two points

  called the enpoints of the segment and all

  the points in between them that are

  collinear with the two points.
• Parallel lines - lines in the same

  plane that never meet.
• Perpendicular lines are lines that meet

  at 90° angles.
• Perpendicular line - lines that intersect that form a right angle