Answer
Please see the work below.
Work Step by Step
We can convert the given angles in degree into radian as follows:
We know that
$1 degree=\frac{\pi rad}{180^{\circ}}$
$\implies 30^{\circ}=30^{\circ}(\frac{\pi rad}{{180^{\circ}}})=\frac{\pi}{6}rad$
similarly
$45^{\circ}=45^{\circ}(\frac{\pi rad}{{180^{\circ}}})=\frac{\pi}{4}rad$
$90^{\circ}=90^{\circ}(\frac{\pi rad}{{180^{\circ}}})=\frac{\pi}{2}rad$
$180^{\circ}=180^{\circ}(\frac{\pi rad}{{180^{\circ}}})=\pi\ rad$
