Geometry Help
 

Circle Arc

This section is about the arc of a circle. The length of an arc of a circle is expressed in linear unites of measurement such as inches or centimeters. Below is a picture of a circle arc showing the arc length in a circle. Later on, we will discuss the formula for arc length in a circle.

Circle Arc

Measuring the arch length of a circle

Degrees are used to represent the measure of an arc. A degree is a unit of measurement obtained by dividing one complete revolution (circle) into 360 equal parts. Each part is called a degree.

How many degrees does a circle have?

A circle has 360 degrees. This can be assumed for all circles. The measure of a circle is 360 degrees. Therefore, the measure of a semi circle is 180 degrees.

Definition of a major arc of a circle

A major arc of a circle is an arc with a degree measure of greater than 180 degrees but less than 360 degrees (see picture of a circle above).

Definition of a minor arc of a circle

Likewise, the definition of a minor arc of a circle is an arc with a degree measure of less than 180.