A sector is a fraction of a circle. The angle in the sector is a fraction of 360°. This sector has an angle of θ°. The fraction of the circle is \(\frac{θ}{360}\) The area of the sector will ...

The circumference of a circle = \(\pi d\) or \(2\pi r\). Look at the sector of the circle shown below. To calculate the length of the arc, we need to know what fraction of the circle is shown.