What Are Loci in Geometry?
A locus is a set of points that satisfies a specified condition. Here are some loci you need to know:
Theory
Loci
- Circle:
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All points on a circle have the same distance from its center point.
- Ellipse:
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The sum of the distances to the two focal points is the same for all points on the ellipse.
- Equidistant Line:
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All points that are equidistant from two specified points.
- Parallels:
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All points equidistant to a specified straight line.
- Bisector:
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All points equidistant to two specified lines.
- Circle of Apollonius:
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Every angle that spans a line segment. Added together, these angles create a circle.
On exams, you may be asked what locus is being described. For that reason, it will be useful to remember what defines the different loci.
