Answer:
B 30°
Explanation:
come now.
the sum of all angles around one point on one side of a line is 180°.
why ?
because any line with a point can be seen as a diameter of a circle with that point as center.
and every side of the line represents then a half-circle.
and a half-circle stands for 360/2 = 180°.
so,
180 = (2x + 70) + (x - 10) = 2x + 70 + x - 10 = 3x + 60
120 = 3x
x = 40
2x + 70 = 2×40 + 70 = 80 + 70 = 150°
x - 10 = 40 - 10 = 30°
180 = Q + (2x + 70) = Q + 150
30° = Q