Răspuns :
Formula ariei unui triunghi echilateral : A= l²√3 /4
A=6²√3 /4
A=36 √3 /4
A= 9√3 (cm²)
[tex]A_{triunghi ~echilateral} = \it \mathbf{ \frac{ {l}^{2} \sqrt{3} }{4} } = \frac{6^{2} \sqrt{3} }{4} = \frac{36 \sqrt{3} }{4} = 9 \sqrt{3} \: {cm}^{2} [/tex]