Writer Mac Barnett and illustrator Jon Klassen are New York Times bestselling authors whose books Extra Yarn and Sam and Dave Dig a Hole are Caldecott Honor Books. Triangle is the first of a series of three books on friendship aimed at children from ages 5 through 8 years of age. Given the accolades already heaped upon this dynamic duo, the future looks very bright for them.

Triangle is a playful soul who just cannot wait to visit his friend Square
and play a "sneaky trick" on him. He pretends to be a snake and scares him. Square then follows Triangle back to his place where he blocks his door, knowing Triangle is afraid of the dark.

There are many children who will see this picture book as a celebration of play in the lives of friends. Others might see it as a probe of the harm done by competition. Either way, this book is creatively designed with its emphasis on all sizes of triangles and squares plus some shapes with no names.