4th December 2019

14

# What is an arc angle?

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