As the value of  approaches the value of , approaches .

In the relationship , if approaches .

This means that approaches .

If approaches ,then the eccentricity of an ellipse is defined as also approaches .

As  approaches close to , and the foci is near to the center of ellicpse which becomes less elongated and more circular.

When the resulting figure is a circle.

The ellicpse is nearly circular when approaches the value of .