- A110°
- B190°
- C50°
- D60°
Step-by-Step Solution
∠ACD = ∠A + ∠B, so 120° = 70° + ∠B and ∠B = 50°. (60° is the interior angle at C.)
Answer: C) 50°
Look at the figure. The exterior angle is 120° and ∠A = 70°. Find ∠B.
Class 9Exterior Angle of a TriangleGeometry — Lines and Angles
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