x^2+y^2=4((sqrt)(x^2+y^2-y))

I understand the concept of how to do this, I for some reason just can't get past plugging in the constants to convert it.

So far I have... r^2=4((sqrt)(r^2-rsin(t))

I also need to graph this equation once it is converted, so the equation must be set to r, if I'm thinking correctly. Also, I don't understand how to graph this equation using a TI-83, or similar, as you can't input r as a value.

Please help!! Thank you.