data-ad-format="horizontal">



 
Major and Minor Arcs
Definition: Given two points on a circle, the minor arc is the shortest arc linking them. The major arc is the longest.
Try this Drag one of the orange dots. Note how the points define both a major and minor arc.

Two points lying on a circle actually define two arcs. The shortest is called the 'minor arc' the longer one is called the 'major arc'. In the figure above, if you were to refer to the 'arc AB' you could mean either one. Typically, if you don't specify which, readers will assume you mean the minor (shortest) arc. If there is a possibility of confusion, you should state which one you mean.

Another way to avoid confusion is to have another point on the arc and use all three to define it. For example 'arc AQB', would not be in doubt since the point Q would lie on only on one of the two possible arcs.

When the major and minor arcs are the same length, they divide the circle into two semicircular arcs.
See Semicircle definition. Under these circumstances neither arc is considered to be the major or minor arc.

While you are here..

... I have a small favor to ask. Over the years we have used advertising to support the site so it can remain free for everyone. However, advertising revenue is falling and I have always hated the ads. So, would you go to Patreon and become a patron of the site? When we reach the goal I will remove all advertising from the site.

It only takes a minute and any amount would be greatly appreciated. Thank you for considering it!   – John Page

Become a patron of the site at   patreon.com/mathopenref

Other circle topics

General

Equations of a circle

Angles in a circle

Arcs