Answer:40
Explanation:
See angle 1 = 65°
Angle 2 = 60°
We know in a triangle all angle count 180°
So angle 3 = 55°
Now in a straight line all angle count 180°
So angle DBC + angle 3 + remaining angle along the line m will count 180°
Now angle 6 and remaining angle along the line m will be equal as 'm' ?and 'b' are parallel lines and t is intersecting them so it subtend equal angles.
Angle 6 = 85° so remaining angle along the line m is also 85°
We know angle DBC + angle 3 + rem. angle = 180°
Or 55° + 85° + angle DBC = 180°
Therefore, angle DBC = 40°
Hope it helps!!!