[latex]A_{square}=20cm^2 \ l^2=20 Rightarrow l= sqrt{20}= 2 sqrt{5}cm \ d_{square}=l sqrt{2} Rightarrow d_{square}=2 sqrt{5}* sqrt{2} \ oxed{d_{square}=2 sqrt{10}cm} [/latex]

A=20  A=l²=>l=√A=√20=2√5 D o putem afla cu teorema lui Pitagra: D²=l²+l² D²=20+20=40 D=√40=2√10