Melody

That is really nice of you to say Pangolin.  Your solution is impressive as well.

Both of our solutions require a lot of geometry knowledge.  Especially if you were doing it under test conditions and could not look things

up.

For mine, and I think yours as well, the answerer would have to know that the point I is the centre of an incircle.  

For mine, an answerer needs to know the perpendicular distance formula. 

This was an interesting question and I am glad I was pushed to answer it without using trigonometry.

It would of course be nice to get proper feedback from the asker.  

I have sent you a private message. 

Certainly if AoPS is written into the question or into a link address then it is an AoPS question.

There are other more subtle ways to tell as well.

Thanks Grace  

Firstly AvenJon I would like to welcome you to the forum.  I know you have answered a lot of question but you have only been here for a month :)

 I have some responses.

1. If people post questions that they find a bit difficult and then answer them themselves they are reinforcing their own learning so I do not have a problem with this.  Learning is more fun if you can give yourself a point.  

2. Wrong answers are annoying but I would not like all the answers to be correct either.  Askers have a responsibility to decide for themselves if the answer should be accepted or not.  

3. Yes, answers without solutions should not be here.  Then again students often do not learn from full solutions either.  Half-done solutions are usually best but if people choose to half do a question they should know how to finish it.  All too often people give 'hints' when they are incapable of doing the question for themselves.  I think that this behavior is super rude.

4. Aops questions are banned, or at the very least, discouraged. But I am surprised at you saying this as I just saw you answer an undisguised Aops question.  I have blocked that question and answer from sight but I know the asker, MathSolverForLyfe has already seen your response. [which, now I look again, was never intended to be too helpful anyway  ;) ]