Odpowiedź:
d=a√2
d - przekątna kwadratu
a - bok kwadratu
[tex]20 \: cm = a \sqrt{2} \: \: \: \: \: | \div \sqrt{2} \\ a = \frac{10}{ \sqrt{2} } \: cm \\ a = \frac{10}{ \sqrt{2} } \times \frac{ \sqrt{2} }{ \sqrt{2} } \: cm \\ a = \frac{10 \sqrt{2} }{ 2} \: cm \\ a = 5 \sqrt{2} \: cm[/tex]
P=a*a
P - pole kwadratu
P [tex] = 5 \sqrt{2} \: cm \times 5 \sqrt{2} \: cm = 25 \times 2 \: cm^{2}= 50 \: cm^{2}[/tex]
