Point3d point1 = new Point3d(1, 2, 3); Point3d point2 = new Point3d(4, 5, 6); double distanceSquared = point1.DistanceToSquared(point2);In this example, we create two 3D points and then calculate the squared distance between them using the DistanceToSquared method. Package library: This method is part of the RhinoCommon library, which is a .NET SDK for developing Rhino plug-ins in C#. RhinoCommon is included with the Rhino 3D software.