The Purplemath website has been extremely helpful for Algebra. We have been searching on the website for basic Geometry terms (e.g., collinear, coplanar, etc.), but could not find this information. Is this information available on your website? (We would prefer to use your website since the explanations are excellent.) If not, can you please refer us to a Geometry website that can explain Geometry the way your site explained Algebra?
Thank you so much for your help!