[tex]a=8cm\\b=2cm\\\alpha = 45\\\\P=a*b*sin\alpha\\P=8cm*2cm*sin45\\P=16cm^2*\frac{\sqrt2}{2}=8\sqrt2cm^2\\\\2cm=h\sqrt2\\h=\frac{2cm}{\sqrt2}=\sqrt2cm\\P=ah\\P=8cm*\sqrt2cm=8\sqrt2cm^2[/tex]
Odp. C, poniewaz [tex]\frac{16}{\sqrt2}cm^2=\frac{16cm^2}{\sqrt2}*\frac{\sqrt2}{\sqrt2}=\frac{16\sqrt2cm^2}2=8\sqrt2cm^2[/tex]
