Question

Calculati perimetrul unui patrat ce are aria egala cu $(4- 2\sqrt{3} ) cm^{2}$

Answer 1

$A= l^{2} \Rightarrow l= \sqrt{A} = \sqrt{4-2 \sqrt{3} } = \sqrt{3-2 \sqrt{3}+1 }= \sqrt{( \sqrt{3}-1) ^{2} }= \\ =| \sqrt{3}-1|= \sqrt{3}-1~(cm). \\ \\ P=4l=4( \sqrt{3}-1)= 4 \sqrt{3}-4~(cm).$