Length of a function using integrals

Find the length of the cardioid r=1+sinO (sorry I wish i knew how to use all the symbols)

I know that

L= integral of [r^2 +(dr/dO)^2]^1/2 dO (from 0 to 2pi)

= integral of [1 + 2sinO + sin^2(O) +cos^2(O)]^1/2 dO...

=integral of (2+2sinO)^1/2 dO from 0 to 2pi,

... then I get stuck on simplifying do I can something I can integrate. I know to multiplying and dividing by the integrand (2-2sinO)^1/2. Can't seem to remember how to do this from high school. Any help would be great. Thanks.