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Webster 1913 Edition
Pentagon
Pen′ta-gon
,Noun.
(Geom.)
A plane figure having five angles, and, consequently, five sides; any figure having five angles.
Regular pentagon
, a pentagon in which the angles are all equal, and the sides all equal.
Webster 1828 Edition
Pentagon
PEN'TAGON
,Noun.
1.
In geometry, a figure of five sides and five angles.2.
In fortification, a fort with five bastions.