d = 19 cm
________
A = ?
Formulă pentru diagonala pătratului:
[tex]\bf\red{\boxed{d=l\sqrt2}}\\[/tex]
[tex]l\sqrt2=19\\l=\frac{19}{\sqrt2}=\frac{19\sqrt2}{2}=\frac{19\times1,4}{2}=\frac{26,6}{2}=8,8\:cm\\[/tex]
Aria pătratului:
[tex]\bf\blue{\boxed{\boxed{A=l^2}}}[/tex]
[tex]A=l^2=8,8^2=\bf77,44\:cm^2\\[/tex]
Succes! ❀
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