Something really good to remember about trigonometry is SOHCAHTOA. I won’t dive into too much detail about it, but you should google it for future assignments.
Anyways,
tan50°=14/AB ABtan50°=14 AB=14/tan50° AB=11.75
cos50°=14/AC ACcos50°=14 AC=14/cos50° AC=21.78
For the measure of angle C you can use a theorem called the third angle theorem. In every single possible triangle, the sum of all three angles adds up to 180°. You can set up an equation like so...