Perpendicular
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Two lines, vectors, planes, etc. that intersect at a right angle are said to be perpendicular.
Perpendicular is an elementary-school-level concept. It is listed in the California State Standards for Grade 4.
Prerequisites
| Intersection: | (1) In set theory, the intersection of two or more sets is the set of elements common to all sets. (2) In geometry, the intersection of two or more regions is the region that is common to all regions. |
| Line: | A line is the infinite extension in both directions of a line segment, giving the path of shortest distance between two points in Euclidean space. |
| Right Angle: | A right angle is an angle that measures exactly 90 degrees. |