Interesting math topics for research paper?

For my calculus cl I have to write a 10 page paper on a math topic. My teacher just shot down my topic, so I need another one. I would like something interesting since after the paper we are giving a presentation on our topic to the school, like a math fair. I did this last year so it is not new to me. My teacher did not like my topic last year, so I would like something awesome to make up for last year and blow her away! Topics that have already been done: cryptography, symmetry, elasticity, fractals, fib. seq., golden ratio, bubbles, games... I'm just looking for some inspiration! Thanks in advance!