Topic: Isometric Circle, Hand Geometry vs ISOCIRCLE Comparison

[Matthew H]

Why is there a different shape between AutoCAD's "ELLIPSE, ISOCIRCLE" command and creating an isometric circle using hand taught methods.

Please see the attached files for reference.

File "Isometric-Circle.jpg"
File "Isometric-Circle.dwg"

Which one is correct?
How can you create the "ELLIPSE, ISOCIRCLE" geometry by hand.

Thank you,
Matthew H.

[Crank]

The geometry by hand (4 arcs) is a approximation.

An isometric circle is a true ellipse, a curve in one equation.

Code: [Select]

X^2     Y^2
----- + ----- = 1
A^2     B^2
Where A and B are the minor and major radius.

If A=B you'll get a circle.