Geometric shapes are probably the most common scientific source for artistic inspiration. Since Ancient civilisations lines, angles, surfaces and solids (the shapes) are used in fine arts as symbols and their symbolism has been enriched all over the centuries by the particular style of each artist. More recently, especially after the arrival of cubism, geometric shapes are also used as an economic way of expression, associated with light and dark (white and black) and with the various colours coming from the decomposition of the natural radiation.

Also Algebra, the branch of mathematics in which letters and symbols are used to represent quantities (the number) plays an important role in theoretical and plastic arts research and constitutes a major basis for artistic creation.

Some of the masterpieces of Almada Negreiros and Lima de Freitas are beautiful examples of the fascination exerted by numerical symbols and geometric shapes in pictorial Art. We will try to describe them in detail under a unifying and imagery rich look in such a way as to obtain an accurate picture of the artist message.