Answer:
∠ A = 62°
Explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
116° is an exterior angle of the triangle, then
3x - 13 + 2x + 4 = 116
5x - 9 = 116 ( add 9 to both sides )
5x = 125 ( divide both sides by 5 )
x = 25
Then
∠ A = 3x - 13 = 3(25) - 13 = 75 - 13 = 62°