What's Your Angle, Pythagoras? book cover image

What's Your Angle, Pythagoras?

  • 795

By: Julie Ellis / Illustrated by: Phyllis Hornung

Discover the secret of triangle that's juuust right

Young Pythagoras can't seem to stay out of trouble. Every time he tries to help, people get angry. What's a curious kid to do?

On a trip to Egypt, Pythagoras' curiosity helps him discover the secret of the right triangle. A clever introduction to the Pythagorean Theorem.

Look Inside the Book:

Author & Illustrator Bios:

Julie Ellis, author

Julie Ellis is the author of many books for children, including What's Your Angle, Pythagoras?, which she wrote as a way to show her daughter the uses of the Pythagorean Theorem. She lives in New Zealand.

Read more about Julie.

Phyllis Hornung, illustrator

Phyllis Hornung graduated from the Columbus College of Art & Design with a degree in illustration. She currently resides in Los Angeles where she spends most of her time drawing and painting. When she's not hard at work painting, she can be found browsing bookstores, reading, watching movies, or playing video games.

Read more about Phyllis.

Awards & Honors:

  • Learning Teachers' Choice Awards for Children's Books
  • Science Books & Films Best Books for Children
  • ABC Best Books for Children

Editorial Reviews:

School Library Journal

A fictionalized look (in spite of the CIP designation) at Pythagoras as he discovers his famous theorem. He is depicted as a curious boy who travels with his father from Samos to Alexandria, where he meets a builder named Neferheperhersekeper, who introduces him to the right angle. He begins to experiment, observing and noting the fixed and unvarying mathematical nature of triangles–right triangles, to be precise. The cartoon illustrations capture the dress, homes, and sailing ships in a warm and clear palette. Ellis includes delightful puns for those who are keen on wordplay. Sticklers be warned: there is lots of dialogue, but in the context of the story, it works well and helps to explain the math. This clear and interesting explanation of the theorem is a wonderful read.

Book Links

As young Pythagoras learns about temple architecture and shipping routes in ancient Greece, he discovers how to accurately measure the sides of a right triangle. This handsomely illustrated explanation of the Pythagorean Theorem will resonate most with readers who are already aware of the equation.

Journal of Children's Literature

Information about the childhood of the musician, astronomer, philosopher, and mathematician Pythagoras is unknown. But that doesn't stop Ellis from imagining events that might have led to his discoveries. It's reasonable to assume the boy must have had an active, inquiring mind--a curiosity about the way the world works. So, this story has Pythagoras trying to figure out how to build bases to support columns that will be straight rather than the crooked ones he has seen; knotting and manipulating ropes to make triangles with different angles; discovering through experimentation the formula for a right triangle; and then using that formula to figure distances. Readers will remember practical applications of the Pythagorean Theorem and might begin thinking about what circumstances other famous people encountered as children that could have led to the way they thought and behaved.


Download the Cover


ISBN: 978-1-57091-150-7

ISBN: 978-1-60734-161-1 PDF
For information about purchasing E-books, click here.

Ages: 7-10
Page count: 32
81/2 x 91/2

If you like this book, you’ll enjoy these:
Pythagoras and the Ratios
Sir Cumference Math Adventures