This article explains couple of important properties of triangular numbers, how they can be used in puzzle solving, and how triangular numbers are related to combinations. Concepts are explained in the form of puzzles and graphical illustrations. Triangular numbers are the count of objects that can be arranged in the form of an equilateral triangle. (Just like how square number s are the count of objects that can arranged in the form of a square).
People who know me know that I have a thing for traditional craft. My office and home are a kaleidoscope of handmade items that represent the myriad local cultures from all over India – paper pinwheels from Haryana, thatch mats from Assam, ceramics from Uttar Pradesh, Madhubani paintings from Bihar, table runners from Rajasthan, and so on.
Here is an illustrated story from Pratham Books' Storyweaver platform.
In a canopy forest in India, the Up World and Down World have always been suspicious of each other. But it all changes when Gopa the dormouse drops her book by accident on Fatima’s head. A story about the biodiversity of the canopy forests and friendship.