- A20°
- B60°
- C80°
- D40°
Step-by-Step Solution
3k + 4k = 140°, so k = 20°. The angles are 60° and 80°; the smaller is 60°. (40° is the interior angle at C.)
Answer: B) 60°
The exterior angle at C of △ABC is 140°, and the two interior opposite angles are in the ratio 3 : 4. Find the smaller of them.
Class 9Exterior Angle of a TriangleGeometry — Lines and Angles
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