Помогите пожалуйста, по формуле герона

$p= \frac{\sqrt{ 2}+1+1}{2} = \frac{\sqrt{2}+2}{2} = \frac{1}{\sqrt{2}} +1 \\S=\sqrt{(\frac{1}{\sqrt{2}} +1)*(\frac{1}{\sqrt{2}} +1-1)*(\frac{1}{\sqrt{2}} +1-1)*(\frac{1}{\sqrt{2}} +1-\sqrt{2})}=\\=\sqrt{( \frac{1}{\sqrt{2}}+1)*( \frac{\sqrt{2}}{2} )^2*(\frac{1}{\sqrt{2}} +1-\sqrt{2})}=\frac{\sqrt{2}}{2}*\sqrt{ (1+\frac{1}{\sqrt{2}})(1-\frac{1}{\sqrt{2}}) }=\\=\frac{\sqrt{2}}{2}*\sqrt{ \frac{1}{2} }= \frac{1}{2} =0,5$
Ответ:0,5