As shown in the figure, e is a point in the square ABCD. If △ Abe is an equilateral triangle, then ∠ BCE=

As shown in the figure, e is a point in the square ABCD. If △ Abe is an equilateral triangle, then ∠ BCE=

∠BCE=30°
Reason: ∵ quadrilateral ABCD is a square
∴∠ABC=90°
∵ △ Abe is an equilateral triangle
∴∠ABE=∠AEB=60°
∵∠ABE+∠CBE=90°
∴∠CBE=30°
∵∠AEB+∠BEC=180°,∠AEB=60°
∴∠BEC=120°
∵∠BEC+∠BCE+∠CBE=180°
∠CBE=30°
∴∠BCE=30°