geogebra books

in the applets of the following geogebra books that are dynamic and interactive, one may manipulate certain elements of the construction and analyse the different results obtainable; in other books, the constructions and exercises are solved step-by-step, allowing the user to move backwards or forward in its resolution.

the text in most of the applets is in portuguese, but all the constructions, none the less, are understandable.