Ok so the 3 angles are 50, x+72, and x+82.
We can find x first;
The angle sum of a triangle is 180 degrees,
So 50 + (x+72) + (x+82) = 180
Simplify the left side to get
2x + 204 = 180
2x = - 24
x = -12.
Angle A is x + 72, so A = -12 + 72
= 60 degrees
So A is 60°
Hope this helped.
