Equation of a circle touching line x=-1 =3 y=3,................................

x=-1 and x=3 are touching the circle.so the midpoint of the perpendicular line joining these two lines will be the centre,but there are infinitely many lines.but also it touches y=3,so plot a cartesian plane, draw 3 lines,and see that radius of circle should be 2(since centre should lie on the midpoint of line joining the 2 lines) and also 2 from y=3,so centre is (1,1) and radius is 2.so (x-1)^2 +(y-1)^2 =4 is the equation of circle.i think it helped you!!!