Resposta:
[tex]\textsf{Leia abaixo}[/tex]
Explicação passo a passo:
[tex]\mathsf{A = \dfrac{3L^2\sqrt{3}}{2}}[/tex]
[tex]\mathsf{A = \dfrac{(3).(12)^2.(1,7)}{2}}[/tex]
[tex]\mathsf{A = \dfrac{(3).(144).(1,7)}{2}}[/tex]
[tex]\mathsf{A = \dfrac{734,4}{2}}[/tex]
[tex]\boxed{\boxed{\mathsf{A = 367,20\:cm^2}}}[/tex]
