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In an isosceles triangle ΔABC, AB = AC and ∠A = 80°. The bisector of ∠B and ∠C meet at D. The ∠BDC is equal to.

In an isosceles triangle ΔABC, AB = AC and ∠A = 80°. The bisector of ∠B and ∠C meet at D. The ∠BDC is equal to. Correct Answer 130°

Triangles mcq solution image
∵ AB = AC
   Point D is the incenter
∴ ∠BDC = 90° + $$\frac{1}{2}$$ ∠A
              = 90° + $$\frac{1}{2}$$ × 80°
              = 90° + 40°
              = 130°

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