# What are triangular numbers and square numbers?

**Triangular numbers**are those numbers which can be arranged in triangles. The example of triangular numbers are 1,3,6,10,15......

$\mathrm{Triangular}\mathrm{number}3\mathrm{can}\mathrm{be}\mathrm{written}\mathrm{as}-\begin{array}{ccc}& \xb0& \\ \xb0& & \xb0\end{array}$

**Square numbers**are those numbers which can be arranged in squares. The example of square numbers are 1,2,4,9,16,25,...

$\mathrm{Square}\mathrm{number}4\mathrm{can}\mathrm{be}\mathrm{written}\mathrm{as}-\begin{array}{cc}\xb0& \xb0\\ \xb0& \xb0\end{array}$

Regards

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