Adjacent
Pronunciation: /əˈdʒeɪ.sənt/ Explain
Two features on a shape are adjacent if
they are next to each other.^{[1]}
Adjacent parts of a polygon
Figure 1  Polygon 

In the polygon in figure 1:
 the angles A and B are adjacent,
 the sides g and h are adjacent, and
 angle A is adjacent to side g.
However,
 angle A is not adjacent to angle C,
 side g is not adjacent to angle D, and
 sides g and i are not adjacent.

Adjacent Angles on Intersecting Lines
Click on the blue points to change the figure. Click on the check boxes to turn pairs of adjacent angles red.
Which of the angles are adjacent (share a ray)?
 Manipulative 1  Adjacent Angles Created with GeoGebra. 

Given two
intersecting
lines, two angles formed by the intersecting lines are adjacent if they are on the
same side of one of the lines.

Adjacent Arcs
Click on the blue points and drag them to change the figure.
Which of the arcs are adjacent (share an endpoint)?
 Manipulative 2  Adjacent Arcs Created with GeoGebra. 

Two arcs of the same curve are adjacent if they share an
endpoint.

References
 McAdams, David E.. All Math Words Dictionary, adjacent. 2nd Classroom edition 201501084799968. pg 11. Life is a Story Problem LLC. January 8, 2015. Buy the book
Cite this article as:
McAdams, David E. Adjacent. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/a/adjacent.html.
Image Credits
Revision History
12/21/2018: Reviewed and corrected IPA pronunication. (
McAdams, David E.)
6/12/2018: Removed broken links, changed Geogebra links to work with Geogebra 5, updated license, implemented new markup. (
McAdams, David E.)
10/12/2010: Added "Adjacent angles on intersecting lines" and "adjacent arcs". (
McAdams, David E.)
12/24/2009: Added "References". (
McAdams, David E.)
7/12/2007: Initial version. (
McAdams, David E.)