Răspuns :
[tex] A_{tot} =2 A_{baz}+ A_{lat} \\ A_{baz}= \frac{a^2 \sqrt{3} }{4}= \frac{49 \sqrt{3} }{4} \\ A_{lat}= P_{baz}*H =3*7*5 \sqrt{3}=105 \sqrt{3}cm^2 \\ A_{tot}= \frac{49 \sqrt{3} }{2}+105 \sqrt{3}= \frac{259 \sqrt{3} }{2}cm^2 [/tex]