BdMO Online Forum

In a isosceles triangle ABC , AB =AC . D is a point on AB so that , AD = DC = BC . What is the value of angle A ?

As you can see in the figure, the angles with the same colour have the same magnitude. (Because the opposite sides are equal)
So, it's not hard to notice that $\angle B = 2 \angle A$. Since, $AB = AC$, so $\angle C = \angle B = 2\angle A$.
So, $\angle A + 2\angle A + 2 \angle A = 5\angle A = 180^{\circ} \Rightarrow \angle A=36^{\circ}$.

Oh! Read the statement wrong! But, I see you re-posted it.
Why did you do that? It was already answered yesterday here! :-s

Raiyan saying to Labib ,
Sorry for the in convenience,
But although your answer is correct and thanks for that.

I fixed the solution. Guess Asif's solution was not right, but you could've waited for a solution or asked for help again in the same thread.
Anyway, I'll just ignore it and hope you'll be careful from the next time.

I actually mixed one with another . After I saw this question , although I knew the answer , to be sure I tipped it in the forum . But then I saw that it didn't have anything inside it . So , I posted it again . Also I don't think that I did do any change in it . Could you tell me what I changed ?

I don't understand what you are trying to say. I'm guessing, you could not find the previous post, so you re-posted the problem.
If I guessed correct, for your information, there's an option on the top-left of your screen called "view your posts".
You can find your previous posts there.

And if nobody replies to post, instead of reposting, just post a reply to the post on your own asking for help again.
That will again make the thread visible in the "recent posts" section and hopefully somebody will answer then.

After joining the forum I didn't understand anything and didn't use it . After starting using it , I named some of my posts quite the same . So I posted it by mistakenly thinking that , anything that is posted in the test forum doesn't last long after seeing what I posted in the Test forum have vanished . But I mistakenly saw another problem . Sorry for that .
If you are not understanding anything what I said , sorry because I could not say anything quite perfectly .

Also, if you're not comfortable with English, you're more than welcome to use Bangla (preferably in Bangla font, maybe with Avro) in anywhere other than "Olympiad level" forum (http://www.matholympiad.org.bd/forum/viewforum.php?f=24). It's expressing your ideas clearly that matters the most