Answer:
19.3
Explanation:
Since the sum of all angles inside of a triangle add up to 180, all three angles add up to 180.
x + 5x + 4x - 13 = 180
Now, we work backwards to figure out what x is.
10x - 13 = 180
Add 13 on both sides
10x = 193
Divide by ten to isolate x
x = 19.3
Since angle A is x, then it is 19.3