Using Programming Languages other than VBA

Sub Example_Diameter()
	' This example creates a Circle object in model space and
	' returns the diameter of the new Circle

	Dim circleObj As AcadCircle
	Dim centerPoint(0 To 2) As Double
	Dim radius As Double

	' Define the new Circle object
	centerPoint(0) = 0: centerPoint(1) = 0: centerPoint(2) = 0
	radius = 5#

	' Create the Circle object in model space
	Set circleObj = ThisDrawing.ModelSpace.AddCircle(centerPoint, radius)

	ThisDrawing.Application.ZoomAll

	MsgBox "The diameter of the new Circle is: " & circleObj.Diameter
End Sub