I was at my dad's house (no internet ) and I needed to find pie to a few more digits then I knew..

I just put 2 points, using arcsin to find them. Whenever teh angle went above X, I knew I had gone too far, backed up one, went to next digit, etc... I got it correct up to about 12 digits... then it went beyond the capabilites of QBasic lol (It started doing it in scientific notation, which didn't give more info.