10.
Apa de ploaie reprezintă capacitatea unui paralelipiped
cu dimensiunile: L = 15m, l = 6m, h = 45cm = 0,45m
Volumul acestui paralelipiped este :
[tex]\it \mathcal{V}=15\cdot6\cdot0,45=40,5\ m^3=40,5\cdot1000\ dm^3=40500\ \ell=405\ h\ell[/tex]
12.
Fie a, b, c dimensiunile paralelipipedului.
[tex]\it 4(a+b+c)=100|_{:4} \Rightarrow a+b+c=25\ \ \ \ (1)\\ \\ d^2=a^2+b^2+c^2=(a+b+c)^2-2(ab+bc+ca)\ \stackrel{(1)}{=}\ 25^2-\mathcal{A}_t=625-\mathcal{A}_t\ \ \ (2)\\ \\ Dar,\ \ d=19\sqrt2 \Rightarrow d^2=(10\sqrt2)^2=100\cdot2=200\ \ \ (3)\\ \\ (2),\ (3) \Rightarrow 625-\mathcal{A}_t=200 \Rightarrow 625-200=\mathcal{A}_t \Rightarrow \mathcal{A}_t=425\ cm^2[/tex]
