Pi is 3.141592653589793... But it really goes on forever and ever, judging by da answer above...

The wind spins the windmill, which in turn spins a generator, which generates the  electricity. Simple as that.

The wind spins the windmill, which in turn spins a generator, which generates electricity from the kinetic energy. Simple as that.

Not much at all. McDonalds may say it has healthy, fresh fruit, but it is just about as bad for you as the rest of mcDonalds