Starred Review for Kirkus Reviews

Everything kids need to know about triangles—vocabulary, explanations and all. Beginning with the definition of a triangle and a breakdown of its parts—sides, angles, vertices—Adler quickly launches into a discussion of angles, even teaching kids how they are named, measured and classified. A clever activity instructs readers to cut out a triangle, any triangle. By tearing off the corners and lining them up so the vertices touch, kids can see that the angles of a triangle always sum 180 degrees. Vocabulary is printed in bold type and defined within the text, each new term building on the ones that have come before: "All three angles in ?ABC…are acute angles. ?ABC is an acute triangle." In the primary-colored digital illustrations, a dark-skinned boy and a light-skinned girl are accompanied by a robot as they progress through the book, drawing and studying triangles. They accumulate materials to make another robot and then identify the angles and triangles that make up its body. Labels and diagrams make the learning easy, while the endpapers show several examples of each type of triangle presented. A final activity challenges readers to use their arms and hands to find and name angles—a turn of the page supplies labeled answers. With lots of layers of information, this is a book that can grow with kids; new information will be accessible with each repeat reading. (Math picture book. 6-10)

School Library Journal Starred Review

Gr 2-4 A straightforward and easy introduction to triangles and angles. There is a lot of repeated information, which will work well with students with different learning styles, and the bold, exciting illustrations will hold kids' attention. Adler relies on the tried-and-true example of a clock in order to explain angles, and most students will easily understand—as long as they are still exposed to analog clocks. The search-and-find illustrations throughout are an added kid-friendly bonus. While important words are printed in boldface and defined throughout the book (e.g., acute angle, isosceles triangle, reflex angle), the book's one drawback is the lack of a glossary; students will have to look back through the text to redefine words. A recommended purchase for any math collection, this title serves as a great update on the subject.— Jasmine L. Precopio, Fox Chapel Area School District, Pittsburgh, PA

ALA Booklist

Adler and Miller, whose previous books include Working with Fractions (2007) and Perimeter, Area, and Volume: A Monster Book of Dimensions (2012), offer a well-organized and brightly illustrated introduction to triangles. The clearly written text moves quickly, stopping occasionally to ask questions. Mathematical terms, such as angle, vertex, equilateral, isosceles, scalene, similar, and congruent, are explained along the way. Miller's digital illustrations feature rounded people and robots working with brightly colored, geometric shapes. Since some early geometry books fudge on the illustrations (roundish shapes for circles, four-sided ones with uneven lines for rectangles), it's a pleasure to find one in which the straight lines are actually straight and the geometric figures are exact and helpfully labeled. While most children will need time and practice to absorb all the ideas introduced here, the orderly presentation of concepts and the precise yet lively illustrations make this book a fine resource for kids learning about triangles and those reviewing what they've learned.

Horn Book

A couple of kids and a pair of robots host this personable introduction to triangles. The usual classroom terms (vertex, congruent, etc.) are presented in bold and clearly defined; Adler gets readers to live the geometric magic by encouraging them to make angles with their arms and fingers. The flat, bold illustrations are, yes, geometric but not without flair.

Kirkus Reviews (Fri Oct 04 00:00:00 CDT 2024)

Everything kids need to know about triangles—vocabulary, explanations and all. Beginning with the definition of a triangle and a breakdown of its parts—sides, angles, vertices—Adler quickly launches into a discussion of angles, even teaching kids how they are named, measured and classified. A clever activity instructs readers to cut out a triangle, any triangle. By tearing off the corners and lining them up so the vertices touch, kids can see that the angles of a triangle always sum 180 degrees. Vocabulary is printed in bold type and defined within the text, each new term building on the ones that have come before: "All three angles in ?ABC…are acute angles. ?ABC is an acute triangle." In the primary-colored digital illustrations, a dark-skinned boy and a light-skinned girl are accompanied by a robot as they progress through the book, drawing and studying triangles. They accumulate materials to make another robot and then identify the angles and triangles that make up its body. Labels and diagrams make the learning easy, while the endpapers show several examples of each type of triangle presented. A final activity challenges readers to use their arms and hands to find and name angles—a turn of the page supplies labeled answers. With lots of layers of information, this is a book that can grow with kids; new information will be accessible with each repeat reading. (Math picture book. 6-10)