Răspuns :
[tex]\it a)\ \ \mathcal{A}=L\cdot \ell=7,48\cdot3,25=24,31\ m^2=243100\ cm^2\\ \\ \\ b)\ \ \mathcal{A}_{plac\breve a}=6\cdot\dfrac{12^2\sqrt3}{4}=6\cdot\dfrac{12\cdot12\sqrt3}{4}=6\cdot3\cdot12\sqrt3=6\cdot36\sqrt3=216\sqrt3cm^2\\ \\ \\ 650\cdot216\sqrt3=140400\sqrt3\approx140400\cdot1,732=243172,8>243100[/tex]
Deci, ar ajunge 650 de plăci.