How Round Is Your Circle?

John Bryant and Chris Sangwin investigate a seemingly simple question: how close is a hand-drawn circle to a perfect one? Using accessible algebraic geometry, the authors demonstrate that the answer depends entirely on the method of construction. A circle drawn with a compass is exact, but one traced by a string or a mechanical linkage may deviate in subtle, measurable ways.

The book serves as a bridge between pure mathematics and practical engineering, exploring the geometry of curves generated by physical mechanisms. The writing is conversational and illustrative, avoiding dense formalism in favor of clear visual explanations and real-world applications. It appeals to readers interested in the hidden mathematics of everyday objects, from drafting tools to industrial machinery, revealing how abstract geometric principles manifest in the physical world.

Description adapted from Open Library bibliographic data ↗.