- A30°
- B105°
- C60°
- D120°
Step-by-Step Solution
The exterior angle at A equals ∠B + ∠C = 45° + 75° = 120°. (60° is the interior angle ∠A.)
Answer: D) 120°
In △ABC, ∠B = 45° and ∠C = 75°. Side CA is produced beyond A. What is the exterior angle formed at 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, D lies on BC. ∠BAD = 30°, ∠B = 45° and ∠C = 50°. Find ∠DAC.In △ABC, ∠B = 60° and ∠C = 40°. AD bisects ∠A and meets BC at D. Find ∠ADC.The exterior angles at B and C of △ABC add up to 250°. Find ∠A.The angles of a triangle are x, 2x and 3x. Find the exterior angle at the vertex whose…In △ABC, ∠A = x, ∠B = x + 10° and the exterior angle at C (BC produced) is 130°. Find…