CIRCLE (Command) | Drawing a circle in AutoCAD | Autocad 2020
2P (2 Point)
This option helps you draw a circle using two endpoints, the distance between those 2 points will be diameter of circle in AutoCAD.
3P (Three Points)
This works absolutely same as 2 points method here you have to define 3 points.
TTR (Tangent, Tangent, Radius)
Creates a circle with a specified radius and tangent to two objects. as tan it may be circle or line etc.
Tan, Tan, Tan
Creates a circle tangent to three objects.