Set of All Points also wrote:

So, no matter where you are on the ellipse, you can add up the distance to point "A" and to point "B" and it will alwas be the same result.

But apart from that, very good pages. The Unit Circle page might deserve to be in the Advanced Maths section. It involves trigonometry, so it's fairly advanced. It depends on how advanced the subject needs to be before it can be called advanced, really.

Some examples of the weird and wonderful shapes that loci can form would be nice.

Thanks guys, I will correct those.

The purpose of "Advanced" is to let the reader know they are expected to have some knowledge of mathematics before reading. This lets me use formulas and simple algebra without much explanation.

I think "if the typical school student read the page would they be in over their heads?" ... if so it should probably be an advanced page. Perhaps around Year 11/12, particularly on elective subjects. But I am still feeling my way on this.

Patrick: I use a variety of programs. Inkscape, Povray, Photoshop, Photoplus.