Beautiful geometry

Thales of Miletus

Triangles of Equal Area

Quadrilaterals

Perfect Numbers and Triangular Numbers

The Pythagorean Theorem I

The Pythagorean Theorem II

Pythagorean Triples

The Square Root of 2

A Repertoire of Means

More about Means

Two Theorems from Euclid

Different, yet the Same

One Theorem, Three Proofs

The Prime Numbers

Two Prime Mysteries

0.999

Eleven

Euclidean Constructions

Hexagons

Fibonacci Numbers

The Golden Ratio

The Pentagon

The 17-Sided Regular Polygon

Fifty

Doubling the Cube

Squaring the Circle

Archimedes Measures the Circle

The Digit Hunters

Conics

3/3 = 4/4

The Harmonic Series

Ceva's Theorem

e

Spira Mirabilis

The Cycloid

Epicycloids and Hypocycloids

The Euler Line

Inversion

Steiner's Porism

Line Designs

The French Connection

The Audible Made Visible

Lissajous Figures

Symmetry I

Symmetry II

The Reuleaux Triangle

Pick's Theorem

Morley's Theorem

The Snowflake Curve

Sierpinski's Triangle

Beyond Infinity

Proofs of Selected Theorems Mentioned in This Book.