Imagine you got an acute-angled triangle ABC. At one side you put a point P, and then you draw right-angled lines like this:
http://i45.tinypic.com/xcrr6h.png
How can I construct P so that a triangle emerges?
http://i50.tinypic.com/254yqhh.png
Allowed stuff: compass and ruler.
Needed stuff: ruler, and something to do a right angle.
Took me over 4 weeks to find it (yes I got it finally!), lets see if SRL can do it faster :p
Edit: you also need to proove your solution. The prize: the fact that you did something you can't seem to find on Google :D
Update: I'm going to give three hints, the same ones my maths teacher gave me: Highlight to view
- Look for similar triangles
- For the algebraic solution: ebook3000.com/Topics-in-Elementary-Geometry_24063.html, chapter 15 (A Closure Problem for Triangles)
- http://i48.tinypic.com/107qrrl.png

