In this introduction to polygons, a triangle convinces a shapeshifter to make him a quadrilateral and later a pentagon, but discovers that where angles and side

The creative examples, simple text, and art in this series help students learn primary math concepts.

Editors' Choice: Books for Youth 1993, Booklist 100 Picture Books Everyone Should Know, The New York Public Library 1995-1996 Utah Children's Picture Book Award

Describes the 1911 fire that destroyed the Triangle Shirtwaist factory in New York's Greenwich Village, the deaths of 146 workers in the fire, and the implicati

In ancient Greece, young Pythagoras discovers a special number pattern (the Pythagorean theorem) and uses it to solve problems involving right triangles.