
An arc is any smooth curve joining two points.^{[1]} This article will focus on arcs of circles. An arc of a circle is sometimes called a circular arc. Any two points on a circle define two arcs. If the two points are on a diameter of the circle, each arc is called a semicircle. If the two points are not on a diameter of a circle, they define two arcs. The larger arc is called the major arc, and the smaller arc is called the minor arc. Adjacent arcs are two arcs that share an endpoint. 
Arcs are measured based on what portion of a whole circle they occupy. A whole circle measures 360° or 2π rad. 'rad' is an abbreviation for radians. An arc occupying 1/2 of a circle would then measure 360° / 2 = 180° or 2π rad / 2 = π rad.

Arc length is defined as the linear length of an arc. For arcs of circles, the arc length is calculated as a portion of the total circumference of the circle. if the arc measures 72°, and the circumference is 22cm, then the arc length is 72°/360° · 22cm = 4.4cm. 
#  A  B  C  D 
E  F  G  H  I 
J  K  L  M  N 
O  P  Q  R  S 
T  U  V  W  X 
Y  Z 
All Math Words Encyclopedia is a service of
Life is a Story Problem LLC.
Copyright © 20052011 Life is a Story Problem LLC. All rights reserved.
This work is licensed under a Creative Commons AttributionNoncommercialShare Alike 3.0 License