Answer:
56.3876 = x
Explanation:
Law of cosines is c^2 = a^2 + b^2 - 2ab*cos(C)
Since we are looking for side a instead of side c though we will rewrite it.
a^2 = c^2 + b^2 - 2cb*cos(A)
We have all necessary parts thankfully, so we can just plug in. In harder problems you may need to find other sides or event he angle.
a^2 = 74^2 + 35^2 - 2*74*35*cos(48)
To get a by itself we take the square root of both sides so
a = sqrt(74^2 + 35^2 - 2*74*35*cos(48))