Question

Aria unui triunghi echilateral cu h= 12 cm este de ....cm2 .

Answer 1

h = l√3/2
12 = l√3/2
24 = l√3
l = 24/√3
l = 24√3/3
l = 8√3 cm.


A = l²√3/4
A = (8√3)²√3/4
A = 64•3√3/4
A = 16•3√3
A = 48√3 cm².



J'espère aidé :)

Answer 2

[tex]h= \frac{l* \sqrt{3} }{2} =\ \textgreater \ 12= \frac{l* \sqrt{3} }{2}=\ \textgreater \ 12*2=l* \sqrt{3}=\ \textgreater \ 24=l* \sqrt{3}\\ =\ \textgreater \ l= \frac{24}{ \sqrt{3} }=\ \textgreater \ l= \frac{24 \sqrt{3} }{3}=\ \textgreater \ l=8 \sqrt{3} cm \\ A= \frac{ l^{2}* \sqrt{3} }{4}=\ \textgreater \ A= \frac{(8 \sqrt{3} )^2* \sqrt{3} }{4}= \frac{64*3* \sqrt{3} }{4} = 48 \sqrt{3} cm^2[/tex]