Been stuck for a while any hints? D:

Thanks in advance

AB=BC=ED

http://i.imgur.com/L0x2S6O.jpg

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- March 20th 2014, 08:39 PMTheProphetsFind value of angle alpha
Been stuck for a while any hints? D:

Thanks in advance

AB=BC=ED

http://i.imgur.com/L0x2S6O.jpg - March 22nd 2014, 06:10 PMjohngRe: Find value of angle alpha
Hi,

The answer is $\alpha=125$. Crucial to the proof is the fact that triangle AEB is isosceles. I tried unsuccessfully to prove this using geometry only. However, there is a simple proof using trigonometry. The first attachment separates this fact as a lemma and the second attachment solves your problem.

Attachment 30490

Attachment 30491