This is a cute book about the friendship of three shapes that gives rudimentary geometry instruction while telling the story. In addition to basic shape names (circle, square, triangle) the text includes usage of words including ‘angle’ and ‘apex’. Toward the end of the book, one of the characters has to come up with an invention in order to resolve the central dilemma.
I wouldn’t categorize this book as STEAM (or STEAM) but I might consider it a proto-STEM book because it places value on knowledge of geometry and on the ability to use ideas and invention to solve problems.
And the kids like it.