Radius of a circle touching lines , whose centre lies in the first quadrant and centre lies on a line
is
Centre lies on angle bisectors of intersecting tangents.
Angle bisector
As centre lies in the first quadrant so center lies on
Centre also lies on , so centre is
Radius = Perpendicular distance form
Radius=
Hence option 3 is correct .
Study 40% syllabus and score up to 100% marks in JEE