An Interesting Geometric Series

Summary

We present a visual proof that ${\sum }_{n=1}^{\infty }{(\frac{1}{\sqrt{2}})}^n=1+\sqrt{2}$.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Ángel Plaza

Ángel Plaza (MR Author ID: 350023) received his masters degree from Universidad Complutense de Madrid in 1984 and his Ph.D. from Universidad de Las Palmas de Gran Canaria in 1993, where he is a Professor in Applied Mathematics. He is interested in mesh generation and refinement, combinatorics, and visualization support in teaching and learning mathematics.