Illuminations: Interactive Geometry Dictionary: Lines in Geometry

Interactive Geometry Dictionary: Lines in Geometry


Lines and points are the two most fundamental structures of geometry. There are many special lines in geometry that are singled out for their interesting properties. Many of these lines are included in this Interactive Geometry Dictionary (IGD). You can use the applets that accompany each definition to explore the definitions of the lines and some of their properties.

To begin, click on any of the lines listed below.

  
 
Type of Line
Line, Segment, Ray   Angle Bisector
Perpendicular Lines   Euler line
Perpendicular Bisector   Simson line
Median    

NCTM Resources

Navigating through Geometry in 9‑12

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