I need help with this ,and it can be more than one answer

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

If u good at math hit me up on insta or sum @basic_jaiden or @ and

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.