ABCD is a square and ABE is a equilateral triangle. find Ang

Question

ABCD is a square and ABE is a equilateral triangle. find Angle DEC a. 30 b. 20 c. 15 d. 45 1.PNG

Bunuel · Answer

DEC=150, so I think the question asks for the measurement of another angle. Anyway below is a diagram with all angles:

RaviChandra · Answer

even i was getting 150...

there is a mistake in the Diagram -- the triangle ABE is outside the square.

After this correction the angle DEC is 30..

thanku so much

Bunuel · Answer

You mean it's like the diagram below? untitled2.PNG Then, yes DEC=30.

RaviChandra · Answer

thanku yes the diagram is same as u mentioned

gurpreetsingh · Answer

four option question is certainly an IIMCAT question.

jlgdr · Answer

Bunuel, would you please elaborate on how you got the angles on the figure? The original Cheers! J

Bunuel · Answer

https://gmatclub.com/forum/download/file.php?id=12721

ABE is an equilateral triangle --> all angles = 60 degrees.
Angles DAE = angle CBE = 90 - 60 = 30 degrees.

Since AD = AE = BE = BC, then triangles DAE and CBE are isosceles: x+x+30=180 --> x=75.

Hope it's clear.

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