Difference between revisions of "Perpendicular"

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==Coordinate Plane==
 
==Coordinate Plane==
Two linear graphs in the Cartesian coordinate plane are perpendicular if and only if one's slope is the negative reciprocal of the other's. This means that their slopes must have a product of <math>-1</math>.
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Two linear graphs in the Cartesian coordinate plane are perpendicular if and only if one's [[slope]] is the negative reciprocal of the other's. This means that their slopes must have a product of <math>-1</math>.
  
 
==See Also==
 
==See Also==
 
*[[Parallel]]
 
*[[Parallel]]
*[[Slope]]
 
 
*[[Skew]]
 
*[[Skew]]
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[[Category:Definition]]
 
[[Category:Geometry]]
 
[[Category:Geometry]]
[[Category:Definition]]
 

Latest revision as of 14:33, 20 October 2007

Being perpendicular is a property of lines in a plane. Generally, when the term is used, it refers to the definition of perpendicular in Euclidean geometry.

Definition

Two lines $l$ and $m$ are said to be perpendicular if they intersect in right angles. We denote this relationship by $l \perp m$.

For non-linear objects

One can also discuss perpendicularity of other objects. If a line $l$ intersects a plane $P$ at a point $A$, we say that $l \perp P$ if and only if for every line $m$ in $P$ passing through $A$, $l \perp m$.

If a plane $P$ intersects another plane $Q$ in a line $k$, we say that $P \perp Q$ if and only if: for line $l \in P$ and $m \in Q$ passing through $A \in k$, $l \perp k$ and $m \perp k$ implies $l \perp m$.

Coordinate Plane

Two linear graphs in the Cartesian coordinate plane are perpendicular if and only if one's slope is the negative reciprocal of the other's. This means that their slopes must have a product of $-1$.

See Also

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