If $a=4$ And $c=7$ , Find the Following Exactly $\sin A^{\circ}$ B) $\cos A^{\circ}$

Essay

If $a=4$ and $c=7$ , find the following exactly. Express your answers as unsimplified radicals when appropriate.
A) $\sin A^{\circ}$
B) $\cos A^{\circ}$
C) $\tan A^{\circ}$