Inside a square ABCD, ∆ BEC is an equilateral triangle.

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Inside a square ABCD, ∆ BEC is an equilateral triangle. If CE and BD intersect at O, then ∠BOC is equal to

1. 60°
2. 75°
3. 90°
4. 120°

Correct Option: B

According to question , we draw a figure of square ABCD in which ∆BEC is an equilateral triangle ,

∠ABC = 90°
⇒ ∠OBC = 45°
[∵ ∠ABC = 2∠OBC]
∠OCB = 60°
[∵ ∠BEC is equilateral]
∴ ∠BOC + ∠OCB + ∠OBC = 180°
∴ ∠BOC = 180° – 60° – 45° = 75°