A practical way to determine the length of an

**arc**in a circle is to plot two lines from the**arc's**endpoints to the center of the circle, measure the**angle**where the two lines meet the center, then solve for L by cross-multiplying the statement: measure of**angle**in degrees/360° = L/circumference.So, how do you find the measure of a central angle?

To

**find**the arc length, when you know the**central angle measurement**and radius, use this**formula**: As you can**see**, the arc length is simply the circumference of a circle (2πR) multiplied by the ratio of the arc**angle**to the full 360**angle**of a circle.What is the formula to find the measure of an arc?

An

**arc measure**is the**measure**of an angle that the**arc**creates in the center of a circle, while an**arc**length is the span of the**arc**. This**measure**can be given in degrees or radians. We can easily convert between the two using the fact that pi radians = 180 degrees.How do I find a length of an arc?

**Method 1**

**Using Measurement of Central Angle in Degrees**

- Set up the formula for arc length.
- Plug the length of the circle's radius into the formula.
- Plug the value of the arc's central angle into the formula.
- Multiply the radius by 2 π {displaystyle 2pi } .
- Divide the arc's central angle by 360.