Question

a diagonal de um quadrado mede 10√2cm. calcule a area.

Answer 1

$Diagonal(d)\\Lado(l)\\\\\\\boxed{d=l \sqrt{2}} \\\\10 \sqrt{2}=l \sqrt{2} \\\\l= \frac{10 \sqrt{2} }{ \sqrt{2} }\\\\\boxed{l=10~cm}$

$\'Area(A)\\\\A=l^2\\A=10^2\\\\\boxed{A=100~cm^2}$