Question Number 140291 by ajfour last updated on 06/May/21
Commented by ajfour last updated on 06/May/21
$$\:{S}=\:{a}+\frac{{a}}{\mathrm{2}}+\frac{{a}}{\mathrm{4}}+\frac{{a}}{\mathrm{8}}+....... \\ $$$$\:\:\:=\:\mathrm{2}{a}\:. \\ $$
Commented by Dwaipayan Shikari last updated on 06/May/21
$${l}^{\mathrm{2}} =\left({a}+\frac{{a}}{\mathrm{2}}+\frac{{a}}{\mathrm{4}}+..{ad}\:{inf}\right)\Rightarrow{l}=\sqrt{\mathrm{2}{a}} \\ $$