In geometry, an arc is a closed segment of a differentiable curve in the two-dimensional plane; for example, a circular arc is a segment of the circumference of a circle. If the arc segment occupies a great circle (or great ellipse), it is considered a great-arc segment.
The length of an arc of a circle with radius and subtending an angle (measured in radians) with the circle center — i.e., the central angle — equals . This is because
Substituting in the circumference
and solving for arc length, , in terms of yields
An angle of degrees has a size in radians given by
and so the arc length equals
See also
- Arc length
- Other meanings of arc
- Circular-arc graph
External links
- Definition and properties of a circular arc With interactive animation
- A collection of pages defining arcs and their properties, with animated applets Arcs, arc central angle, arc peripheral angle, central angle theorem and others.
- Weisstein, Eric W., "Arc" from MathWorld.
ar:قوس (هندسة)
ast:Arcu (xeometría)
be:Дуга (геаметрыя)
ca:Arc (geometria)
da:Cirkelbue
eo:Arko (geometrio)
it:Arco (geometria)
mr:कंस (चाप)
nl:Boog (meetkunde)
no:Bue (geometri)
nn:Boge
km:ធ្នូរង្វង់
pl:Łuk (matematyka)
pt:Arco (matemática)
sl:Krožni lok
sv:Cirkelbåge