Find the length of the common chord of the circles `x^2+y^2+2x+6y=0` and `x^2+y^2-4x-2y-6=0`

The length of the common chord of the circles x^(2)+y^(2)-2x+4y-20=0,x^(2)+y^(2)+6x+10y-2=0

The length of the common chord of the circles x^(2)+y^(2)-2x-1=0 and x^(2)+y^(2)+4y-1=0 , is

The length of the common chord of the two circles x^(2)+y^(2)-4y=0 and x^(2)+y^(2)-8x-4y+11=0 is

The lenght of the common chord of circles x^(2)+y^(2)-6x-16=0 and x^(2)+y^(2)-8y-9=0 is

The distance of the point (1,2) from the common chord of the circles x^(2)+y^(2)+6x-16=0 and x^(2)+y^(2)-2x-6y-6=0 is