W koło o polu 6.25 pi cm2 wpisano czworokąt foremny.Oblicz pole tego czworokąta. POMOCY

[latex]P=pi r^{2}[/latex] [latex]P=6.25pi [/latex] [latex]pi r^{2}=6.25pi[/latex] [latex]r^{2}=6.25[/latex][latex]r=sqrt{6.25}[/latex] [latex]r=2.5[/latex] [latex]r=frac{1}{2}d[/latex]     d- przekątna kwadratu ;] d=2*2,5=5 [latex]d=asqrt{2}[/latex] [latex]asqrt{2}=5[/latex] [latex]a=frac{5sqrt{2}}{2}[/latex] [latex]a=2.5sqrt{2}[/latex] [latex]p=(2.5sqrt{2})^{2}[/latex] [latex]p=6.25*2[/latex][latex]p=12.5[/latex]