matthen:

Draw a perfect triangle on a piece of paper, and then draw around the triangle free-hand. Try to make each new shape closely match the previous one, including its imperfections. You’ll find wavy patterns developing (just like doing the same with straight lines) which makes a nice picture.  But can you manage to do all this, with the ultimate goal that after 50 lines you will reach a perfect square?  This animation shows a computer program having a go. [code]