ABCD is square and CDE is an equilateral triangle outside the square. What is the value (in degrees) of ∠BEC?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 15°
Here, AB = BC = CE = CD = ED = AD
∠DCB = 90o
∠DCE = 60o (△DCE is equilateral)
∠BCE = 90o + 60o = 150o
∠CBE = ∠BEC [Since BC = CE]
∠BEC = [180° - 150°/2] = 30°/2 = 15o