Question

Repede va rog:Aflati aria unui triunghi echilateral cu inaltimea de 3 cm.Va rog si etapele rezolvarii.

Answer 1

$h= \frac{l \sqrt{3} }{2}$
$3= \frac{l \sqrt{3} }{2}$
l√3=3 x 2
l√3=6
$l= \frac{6}{ \sqrt{3} }$     rationalizam
$l= \frac{6 \sqrt{3} }{3} =2 \sqrt{3}$
$A= \frac{ l^{2}* \sqrt{3} }{4} = \frac{(2 \sqrt{3)²}* \sqrt{3} }{4}$
$A= \frac{12 \sqrt{3} }{4} =3 \sqrt{3}$ cm²

Answer 2

 $A_{\Delta}=\frac{l^2\sqrt3}{4}\;\;\;iar \;\;\;l_{\Delta}=\frac{2h}{\sqrt3}=...=\frac{2\cdot3}{\sqrt3}=2\sqrt3$