Answer:
y = 65°
Explanation:
• At point B, the sum / total of all angles on a straight line = 180° therefore '180° - 120° = 60°' meaning that the bottom left angle of the triangle is 60° (Point B in triangle)
• The sum / total of angles in a triangle is equal to 180° therefore you can calculate the final angle y like this:
180° - (60° + 55°) = 65°
y = 65°
OR
60° + 55° = 115°
180° - 115° = 65°
y = 65°