The Association of Teachers of Mathematics (ATM), based in the United Kingdom, "believes in providing teachers with the resources to help them develop their mathematics teaching in creative and broad-thinking ways." This section on Resources OnLine offers a variety of resources, some of which are available only by purchase online. Some of the free online resources include sample files and programs from ATM CDs on spreadsheets and Interactive Mathematics, as well as some games involving shapes and probability. Films available in Macromedia Flash Player format demonstrate topics such as Polygons, Exploring Halves, Tangrams, and Euclid's Pythagoras Proof. A link to ATM's Convex Polyhedra Website shows 50 of the convex polyhedra that can be made with regular polygons and groups them into 10 families and some suggested activities to try using the images. Some articles from ATM Journals are also available online.