Challenge Level

It is usefult to be able to recreate these patterns on square dotty paper.

Is the way the triangles fit together always going to work with two consecutive triangular numbers?

Why?

Yuu might find it useful to look at the problem on "Sequences and Series".

Is the way the triangles fit together always going to work with two consecutive triangular numbers?

Why?

Yuu might find it useful to look at the problem on "Sequences and Series".