The line joining the points A (0,5) and B(4,1) is a tangent to a circle whose centre is at point (5,4)
(a) find the equation of line AB
(b)find the equation of line through C which is perpendicular to AB
(c)find the co-ordinates of the point of contact of the line AB with the circle
(d) find the equation of the circle
THANKS TO ANY ONE WHO CAN HELP ME OUT!