[tex]\it 1)
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\mathcal{A} =\dfrac{BC\cdot AD}{2}
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a)\ \ \mathcal{A} =\dfrac{8\cdot 16}{2} =64\ cm^2[/tex]
[tex]\it b) \ \ \mathcal{A} =\dfrac{4\sqrt2\cdot 3}{2} =2\sqrt2\cdot3=6\sqrt2\ cm^2
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c) \ \ \mathcal{A} =\dfrac{6\sqrt3\cdot 2\sqrt3}{2} = 6\sqrt3\cdot\sqrt3=6\cdot3=18\ cm^2
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d) \ \ \mathcal{A} =\dfrac{20\cdot 8,2}{2} =10\cdot8,2 =82\ cm^2 [/tex]
