I have been working on developing an online geometry Moodle course as part of the grant that I am currently working under. Every time I develop another Moodle course I learn more and more about the power and versatility of Moodle. The Assignment block is a Moodle function that I was familiar with but had not used. It allows you to design the course so that students can not proceed to the next lesson unless they pass a quiz at the end of each lesson.
I am also using Geogebra, an interactive math website. This will give the students real experience in constructing geometric shapes. They will be able to discover geometric rules by manipulating the geometric shapes they build.