Answer:
x = 55.6
Explanation:
Recall the 3 main trig functions
Sin = opposite / hypotenuse
Cos = adjacent / hypotenuse
Tan = opposite / adjacent
Note that hypotenuse = longest side length 
We want to find angle "x". 
We are given its opposite side length ( 19 ) as well as the adjacent side length 
When dealing with the opposite and adjacent we use tan 
Tan = Opp / Adj
Opp = 19 and Adj = 13
Tan(x) = 19/13
* take the inverse tan of both sides * 
x = 55.6