From SOH CAH TOA, we see that we need to use the cosine ... Rearrange using 'change side, change operation'. We need to move the '12' over to the other side of the equals sign so that we have ...

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 ... using 'change side, change operation'.