Question

Answer the question:

Can a rectangular number be a triangular number. Explain with example.

Answer 1

A rectangular number can also be a triangular number.

For Example: $36$

It can be written as a rectangular number as $36=3\times 12$.

It can be written as a triangular number as $36=1+2+3+4+5+6+7+8$.

Hence, a rectangular number can be written in the form of a triangular number.