In order to derive the formula to calculate the angle at the centre of the sector, the formulae for the arc length and area of a sector can be rearranged so that we can calculate the fraction of ...

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. To do ...

Angle: The measure of the opening between two intersecting lines is called an angle. Unit: The unit of angle is radians or degrees. Angle formula: There are different types of formulas for calculating ...