Answer:
58°
Step-by-step explanation:
Angle sum property of triangle:
The sum of all angles of a triangle is 180°.
x + 69 + 55 + x + 78 = 180
x + x + 69 + 55 + 78 = 180
Combine like terms,
2x + 202 = 180
Subtract 202 from both sides,
2x = 180 - 202
2x = -22
Divide both sides by 2,
x = -22/2
x = -11
∠A = x + 69
= -11 + 69
[tex]\sf \boxed{\angle A= 58^\circ}[/tex]
