Picture book makers Mac Barnett and Jon Klassen go back to basics – the elemental shape of a story – in Triangle.

Triangle sets out one day to play a trick on his friend, Square. But does Square have a plan of his own?

Triangle is the first book in a trilogy so it does feel quite open-ended but like the best picture books you can look for your own answers (I personally don’t believe Square).

In a board casing with thick paper pages that feel saturated with Klassen’s colours the book has an iconic look and is a joy to handle.

Triangle, by Mac Barnett and Jon Klassen, published by Walker, is out now.