Beautiful Mathematics is about beautiful mathematical concepts and creations. Mathematical ideas have an aesthetic appeal that can be appreciated by those who have the time and dedication to investigate. Mathematical topics are presented in the categories of words, images, formulas, theorems, proofs, solutions, and unsolved problems. Readers will investigate exciting mathematical topics ranging from complex numbers to arithmetic progressions, from Alcuin's sequence to the zeta function, and from hypercubes to infinity squared. Do you know that a lemniscate curve is the circular inversion of a hyperbola?   That Sierpiński’s triangle has fractal dimension 1.585… .?   That a regular septagon can be constructed with straightedge, compass, and an angle trisector?   Do you know how to prove Lagrange’s theorem that every positive integer is the sum of four squares?   Can you find the first three digits of the millionth Fibonacci number?  Discover the keys to these and many other mathematical problems.  In each case, the mathematics is compelling, elegant, simple, and beautiful. Who should read Beautiful Mathematics? There is something new for any mathematically-minded person. High school and college students will find motivation for their mathematical studies. Professional mathematicians will find fresh examples of mathematical beauty to pass along to others. Within each chapter, the topics require progressively more prerequisite knowledge. An appendix gives background definitions and theorems, while another gives challenging exercises (with solutions).