Complete the form of the equation in rectangular form

"r= -14 sin theta"

I'm having factoring issues with this one, I got " x^2+(y+7)^2=14 but, when I try to check it, x^2+(y^2+14y+14)=14 doesn't come out the same. What am I doing wrong in the factoring?

The rectangular coordinates of a point are given. Find the polar coordinates(r,theta) of this point with theta expresed in radians. Let r>0 and 0<or equal to theta <2pie

(3,-3{squareroot}3)

I used r=sqrt x^2 + y^2 to get 6

then used tan inverse y/x to get -3sqrt3/3= -pie/3

and got (6,-pie/3)

did I do this correctly?