Geometry from Africa

Mathematical and Educational Explorations

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Paulus Gerdes

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In the first chapter of Geometry from Africa, I present through some examples an overview- necessarily incomplete-of geometrical ideas in African cultures, as manifested in the work of wood and ivory carvers, potters, painters, weavers, mat and basket makers, and of so many other laborious and creative African men and women alike.

In the second chapter of the book I show using examples from Senegal in the west to Madagascar in the southeast, how diverse African ornaments and artifacts, varying from woven knots to symmetrical designs and to infinite decorative patterns, may be used as a starting point to create an attractive educational context in which students may be led to discover the pythagorean Theorem and find proofs of it. I also explore connections to related geometrical ideas and propositions. such as Pappus" theorem, similar right triangles, latin and magic squares.

In chapter three I analyze geometrical ideas inherent in various crafts and explore possibilities for their educational use.Chapters deal with topics such as symmetrical wall decoration in Lesotho and South Africa; house building in Mozambique and Liberia; weaving pyramidal baskets in Congo/Zaire, Mozambique and Tanzania; plaited strip patterns from Guinea, Mozambique, Senegal and Uganda; finite geometrical designs from the Lower Congo region. Exploration of a hexagonal basket weaving technique from Cameroon to Kenya, Congo to Mozambique The theme of the fourth chapter is the geometry of the Southern-central African sand drawing tradition- the drawings are called SONA in the Chokwe language(Northeast Angola).