- Khan Academy
https://pt.khanacademy.org/math/basic-geo/basic-geometry-shapes/basic-geo-geometric-solids/v/counting-faces-and-edges-of-3d-shapes
Ângulos:
https://pt.khanacademy.org/math/basic-geo/basic-geo-angle/basic-geo-angle-types/e/recognizing-angles
Dízimas periódicas:
https://pt.khanacademy.org/math/pt-8-ano/numeros-parte2-8ano/pt-dzimas-peridicas/v/converting-a-fraction-to-a-repeating-decimal