This book provides a deep insight into the world of architecture and design. Instead of complex formulae with magical names like the golden ratio, the authors present simple ubiquitous proportions that were already used in crafts before the industrial revolution. The key to great design is mastering these basic principles. Besides the exercises, the book provides many examples and encourages readers to use simple geometry for better design. The principles described in the book are applied in nine contemporary projects that anybody can recreate.