hi what is the answer for this

Step-by-step explanation:
first find the side length by
considering a triangle under
the square
[tex]l \: = \sqrt{ {3}^{2} + {1}^{2} } = \sqrt{10} \: cm \\ area \: = \: \sqrt{10} \times \sqrt{10} = 10 \: {cm}^{2} \: \: \: \: ans[/tex]