- A50°
- B70°
- C60°
- D120°
Step-by-Step Solution
Interior ∠B = 180° − 110° = 70°, interior ∠C = 180° − 130° = 50°. ∠A = 180° − 70° − 50° = 60°.
Answer: C) 60°
In △ABC, the exterior angles at B and C (formed by producing BC both ways) are 110° and 130°. Find ∠A.
Class 9Exterior Angle of a TriangleGeometry — Lines and Angles
Master this chapter in 30 minutes a day.
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Exterior Angle of a Triangle practice questions
More Class 9 Exterior Angle of a Triangle practice
In the figure, side BA of △ABC is produced to E. The exterior angle ∠EAC is 100° and ∠B…A wall shelf rests on a slanting brace, forming a right triangle with the wall. The…The exterior angle at C of △ABC is 140°, and the two interior opposite angles are in the…In △ABC, BC is produced both ways and the two exterior angles at B and C are equal. What…At most how many of the three exterior angles of a triangle (one at each vertex) can be…