$\cos30^{\large\circ}=\sin 60^{\large\circ}=\large\frac{\sqrt 3}{2}$$,\cos 60^{\large\circ}=\sin 30^{\large\circ}=\large\frac{1}{2}$$,\cos 45^{\large\circ}=\sin 45^{\large\circ}=\large\frac{1}{\sqrt 2}$

$\begin{array}{1 1}0^{\large\circ}\\-30^{\large\circ}\\30^{\large\circ}\\45^{\large\circ}\end{array} $