The 3 Point option is one of the easiest ways to define a new UCS on a given 3D object.
1. Open a drawing with a simple 3D object (Ex: BOX)
2. Type UCS at the command prompt
Command: UCS
Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z Axis] <World>: N
Specify origin of new UCS or [ZAxis/3Point/OBject/Face/View/X/Y/Z]<0,0,0>: 3
Specify origin point <0,0,0>: Pick point
Specify point on positive portion of X-axis <3.5,7.5,0>: pick point for X direction
Specify point on positive Y portion of the UCS XY plane<2.5,8.7,0>: Pick point for Y direction
New UCS
TIP:
You can also click the dropdown beside WCS and click New UCS.
