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Arjun makes an isosceles flag in which the two slanting sides are equal. He says the three angles are 50°, 50° and 80°.
His sister Meera says one of those values is impossible for an isosceles triangle.
Is Arjun's set of angles valid?

Class 9Properties of Isosceles TrianglesGeometry — Triangles
  • AYes, it is a valid isosceles triangle
  • BNo, the sum is not 180
  • CNo, isosceles cannot have an 80° angle
  • DNo, all angles must be equal

Step-by-Step Solution

50 + 50 + 80 = 180 and two angles are equal (50, 50), so it is a valid isosceles triangle.
Answer: A) Yes, it is a valid isosceles triangle

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