Side length of the equilateral triangle (a) = 8 cm, Value of square root of 3 ($\sqrt{3}) = 1.732$

Calculate $a^2/4 = 8^2/4 = 64/4 = 16$. Multiply 16 by 1.732 by treating it as $16 \times (1.7 + 0.03 + 0.002) = 27.2 + 0.48 + 0.032 = 27.712$.

Confusing the area formula for an equilateral triangle $\frac{\sqrt{3}}{4}a^2$ with the perimeter $3a$ or the height $\frac{\sqrt{3}}{2}a$.

In geometry questions, always check if the final answer needs to be rounded or if a specific approximation for irrational numbers like $\sqrt{3}$ or $\pi$ is provided.