In triangle DEF, angle D = 30º, angle F = 60º, and EF = 6. Find DF.
We know angle F , the adjacent side and we are looking for the hypotenuse......we need the cosine
cos F = EF / DF
cos 60 = 6 / DF
1/2 = 6 /DF
DF = 6 / (1/2) = 12
