Oval inscribed to quadrangle

[JuneTheSecond]

To draw ellipse touching inside the parallelogram, trapezoid or quadrangle is
difficult, so I've made and uploaded shapes. You can read explanation and
download here. I hope you enjoy these shapes.
http://www.geocities.jp/visualcalculation/english/ellipseinparallelogram.htm

 

[Paul Herber]

To draw ellipse touching inside the parallelogram, trapezoid or quadrangle is
difficult, so I've made and uploaded shapes. You can read explanation and
download here. I hope you enjoy these shapes.
http://www.geocities.jp/visualcalculation/english/ellipseinparallelogram.htm

That is really nice!