To find area $ A $ use formula:
$$ A = \dfrac{ \sqrt{ 3 } \cdot a^2 }{ 4 } $$After substituting $a = 8\, \text{ft}$ we have:
$$ A = \dfrac{ \sqrt{ 3 } \cdot \left( 8\, \text{ft} \right)^{2} }{ 4 } $$ $$ A = \dfrac{ \sqrt{ 3 } \cdot 64\, \text{ft}^2 }{ 4 }$$ $$ A = \dfrac{ 64 \sqrt{ 3 }\, \text{ft}^2 }{ 4 }$$ $$ A = 16 \sqrt{ 3 }\, \text{ft}^2 $$