Re: An interesting solution

Quote:

Originally Posted by **lord twiggy1**

Hi, this is my first post here, so I'm not sure if I'm posting this in the right place, so bare with me.

A couple of weeks ago my Geometry teacher handed out some extra credit. There was one problem I had a little difficulty. I'm pretty sure because I was overthinking it. We turned the extra credit in today, adn I wanted to know if it was really as hard as it felt or if I was, in fact, over thinking it.

Here's the problem:

http://i163.photobucket.com/albums/t...0/triangle.jpg

Let a denote the angle at A, c the half-angle at C, b the half-angle at B and d the angle at D.

Then c + b + d = and 2c + 2b + a = . You can solve these equations to get a = 2d - and so a = 100 degrees