Find the measure of angle a to the nearest degree. how would you find it?

Remark
The Tangent is the most useful way of doing it, and the simplest in this case.

Givens
Tan(A) = opposite side / Adjacent side
Opposite Side = 14
Adjacent Side = 7

Sub and solve
Tan(A) = 14/7
Tan(A) = 2
A = Tan-1(2)
A = 63.43

That question in the comments is a hard question to answer. This is a calculator question. You have to have a Tangent function on your calculator. Do you? If you do then whatever is written about above it is the inverse tangent which means you are trying to find the angle that makes up the Tangent.

On your calculator follow these keys.
2nd Function 
Tan(
2
=
You should get 63 something when you do that. If you are still having problems just give me another comment.

The answer is (a) 12-2(-1)(6)2(6)=12