- A100
- B50
- C55
- D45
Step-by-Step Solution
Exterior angle = sum of two interior opposite (base) angles = 2 base angle, so base angle = deg.
Answer: B) 50
In an isosceles triangle, the exterior angle at the apex (vertex) is 100°. Each base angle is (in degrees):
Class 9Properties of Isosceles TrianglesGeometry — Triangles
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