As the numbers are known on the opposite and the hypotenuse, then we look for the ratio which uses both these sides (SOH CAH TOA). That ratio is the sine ratio. \(\sin (x^\circ ) = \frac{{opposite} ...

The angles are labelled with capital letters. The opposite sides are labelled with lower case letters. Notice that an angle and its opposite side are the same letter. The sine rule is: \(\frac{a} ...