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Take an even natural number, say, $46$ (or any other even number of your choice). Try to express it as a sum of consecutive odd numbers starting with $1$. Do you succeed?

Without adding, find the sum of $1+3+5+7+9+11+13+15+17+19+21+23+25+27$.

Express $225$ as the sum of $15$ odd numbers.

Without adding, find the sum.

$1+3+5+7+9+11+13+15$

Express$64$ as the sum of $8$ odd numbers.

Express the number $81$ as a sum of odd numbers.

Without doing the actual addition, find the sum of:

$1+3+5+7+9+11+13+15+17+19+21+23$

Name a number which is square as well as triangular.