Question

aria totala a unui cub 36 cm diagonala cubului=?

Answer 1

A totala = 6l^2 ----> L=$\frac{ \sqrt{36} }{6}$ -----> l=1
Dcub= l$\sqrt{3}$ ----D=$\sqrt{3}$

Answer 2

     
$At = 6*l^{2} \\ 6*l^{2}=36 \; cm^{2} \\ l^{2} = \frac{36}{6} \\ l^{2} = 6 \\ l= \sqrt{6} \;cm \\ Calculam \;diagonala \;(d): \\ d= \sqrt{ l^{2} + l^{2} + l^{2} }= \sqrt{ (\sqrt{6})^{2} + (\sqrt{6})^{2} + (\sqrt{6})^{2}}= \\ \\ = \sqrt{6+6+6} = \sqrt{18}= \boxed{3 \sqrt{2} \;cm}$