The circle's equation is x2+y2+2gx+2fy+c=0 Coordinate of centre =(−g,−f) radius =√g2+f2−c
since circle touches both the axes g2=f2 g=±√c Therefore, the coordinate of the centre (−√c,−√c) The equation of the given line is x+y+√c=0 Therefore, intercept AB=√(−√c−0)2+(0+√c)2=√2c