Answer:
60°
Step-by-step explanation:
According to Angle Sum Property of a triangle , sum of the angles of 3 sides of the triangle is always 180°.
Here the angles given are 80° & 40°. Let the 3rd angle be x. So using the Angle Sum Property here ,
40° + 80° + x° = 180°
=> 120° + x° = 180°
=> x = 180° - 120° = 60°
