de ru en cz pl
Erlebnisland Mathematik: Homepage > Exhibition > Experiments > Sum of n

Proofs without words: Sum of \(n\)

Sum of n

A "proof without words" convincingly justifies a mathematical claim just by picture.

Here it is shown that \(1 + 2 + \ldots + n\) is equal to \(\frac{n\cdot(n+1)}{2}\).