
Triangle
Read Aloud for Your Family
Press play, gather the kids, and let the story do the work.
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ABOUT THE CREATORS
About the Author and Illustrator
AUTHOR
Mac Barnett
Author of Caldecott Honor picture books including Extra Yarn and Sam and Dave Dig a Hole.
ILLUSTRATOR
Jon Klassen
Canadian illustrator; the only creator to win both the Caldecott Medal and the Kate Greenaway Medal.
Mac Barnett
Mac Barnett is the author of several Caldecott Honor picture books including Extra Yarn and Sam and Dave Dig a Hole, both illustrated by Jon Klassen. He is also the author of the Brixton Brothers mystery series and lives in California.
Illustrator
Jon Klassen
Jon Klassen is a Canadian-born illustrator and author. He is the only creator to have won both the Caldecott Medal and the Kate Greenaway Medal, both for This Is Not My Hat. He illustrated the Shape Trilogy and lives in Los Angeles.
Who This Book Is For
The book is listed at ages 5 to 9 and works especially well for kids who are ready to listen for the joke that the characters do not see. It also works for adults who want a picture book with the deadpan energy of a Sam and Dave Dig a Hole re-read.
What Happens in the Book
Triangle lives in a triangle house. He walks out the door, past triangle hills, on his way to Squareās square house. He is going to play a sneaky trick on his friend, and the trick is to hiss like a snake at Squareās door. Square does not like snakes.
Square falls for it. Square chases Triangle all the way back to Triangleās house, and that is when the joke flips. Triangle has to laugh it off, because Triangle cannot handle the dark, and Square has just blocked the light coming through Triangleās door. Triangle is the one who has been tricked, and the book ends on a quiet, cozy menace.

Triangle hisses at Squareās door, the trick lands, and Square is already on the way to chasing Triangle home.
Who This Book Is For

The shape worldās muted landscape is part of the joke: the reader sees the reversal before Triangle does.
The book is listed at ages 5 to 9 and works especially well for kids who are ready to listen for the joke that the characters do not see. It also works for adults who want a picture book with the deadpan energy of a Sam and Dave Dig a Hole re-read.
It is less of a fit for kids who want a long, plot-driven story. The text is sparse and the pictures do most of the work. The reader who gets the most out of it is the one who pays attention to the architecture of each spread.
Why It Works for Kids
The book is short on words and long on architecture. Mac Barnett writes the dialogue as if the shapes are not joking. Jon Klassen draws the landscape as if the shapes are not characters. The kid who is paying attention to the architecture of the page figures out the reversal before Triangle does, and that is where the laugh lives.
The art also does a quiet job with the dark. The shape world is mostly beige, blue, and gray, and the spread where Square blocks the door is the first spread where the page actually goes black. The kid who has been reading along does not need the text to feel the temperature change.

The reversal lands at Triangleās door: Square is the one in control now, and Triangle has to talk his way back into the light.
The book is short on words and long on architecture. Mac Barnett writes the dialogue as if the shapes are not joking. ā Triangle
Learn More About This Book
Official & Community
- Candlewick Press (publisher)
- Reviews on Goodreads
- Mac Barnett (author site)
- Jon Klassen on Wikipedia (illustrator)
Frequently Asked Questions
What is the trick in Triangle?
Triangle hisses like a snake at Squareās door. Square is afraid of snakes and chases Triangle home. Square ends up blocking the light coming through Triangleās door, which is the one thing Triangle is afraid of. The book ends with Triangle inside the dark, Square outside the door, and the joke turned around.
Why do kids like the Shape Trilogy?
The books are short, the dialogue is deadpan, and the joke belongs to the listener. Each book has a reversal at the end that the kid can predict before the characters figure it out. Mac Barnettās text and Jon Klassenās art do the same kind of work together that they did on Sam and Dave Dig a Hole.
What is the right order to read the trilogy?
The trilogy reads in the order Triangle, Square, Circle, which is also the order the books were published. Circle brings Triangle and Square back together and adds a third shape. Apple TV+ adapted all three as Shape Island.
What books are like this one?
Try Square and Circle, both by Mac Barnett and Jon Klassen. For similar deadpan humor and reversible joke structure, try Sam and Dave Dig a Hole, Extra Yarn, and I Want My Hat Back, all by the same team.


