Radian

1.1

Radian

Apart from the unit of degrees, angles can be also be measured in the unit of radians

Definition of One Radian


	The angle subtended at the centre of a circle is \(1\) radian if the length of the arc is equal to the radius of the circle.


	\(\begin{aligned} \ x^\circ&=\left( x \times \dfrac{\pi}{180} \right) \text{ rad} \\\\ &=\left( x \times \dfrac{3.142}{180} \right) \text{ rad} \end{aligned} \)


	\(\begin{aligned} \ x \text{ rad}&=\left( x \times \dfrac{180}{\pi} \right) ^\circ \\\\ &=\left( x \times \dfrac{180}{3.142} \right) ^\circ \end{aligned} \)