[tex]l = 100 - 5 \sqrt{8} [/tex]
[tex]l = 100 - 5 \times 2 \sqrt{2} [/tex]
[tex]l = 100 - 10 \sqrt{2} [/tex]
[tex]l = 10(10 - \sqrt{2} ) \: cm[/tex]
[tex]a = {l}^{2} [/tex]
[tex]a = {(100 - 10 \sqrt{2} )}^{2} [/tex]
[tex]a = {100}^{2} - 2 \times 100 \times ( - 10 \sqrt{2} ) + \\ + ({10 \sqrt{2}} )^{2} [/tex]
[tex]a = 10000 + 2000 \sqrt{2} + 200[/tex]
[tex]a = 10200 + 2000 \sqrt{2} [/tex]
[tex]a=100(102+20\sqrt{2}) \:{cm}^{2}[/tex]
