1 )
[tex]volume = 20 \times 5 \times 8[/tex]
[tex]volume = 800 \: \: {m}^{3} [/tex]
[tex]surface \: \: area \: = 4 \times 20 \times 8[/tex]
[tex]surface \: area \: \: = 640 \: \: {m}^{2} [/tex]
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2 )
[tex]v = 15 \times 3 \times 4[/tex]
[tex]v = 180 \: \: {m}^{3} [/tex]
[tex]s \: a \: = 4 \times 15 \times 4[/tex]
[tex]s \: a \: = 240 \: \: {m}^{2} [/tex]
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3 )
[tex]v = ( \frac{1}{2} \times 4 \times 5) \times 10 \\ [/tex]
[tex]v = 100 \: \: {m}^{3} [/tex]
[tex]s \: \: a = (10 \times 5) + (10 \times 4) + (10 \times \sqrt{41} ) \\ [/tex]
[tex]s \: a \: \: = 50 + 40 + 10 \sqrt{41} [/tex]
[tex]s \: a \: \: = 90 + 10 \sqrt{41} [/tex]
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4 )
[tex]v = ( \frac{1}{2} \times 3 \times 4) \times 7 \\ [/tex]
[tex]v = 42 \: \: \: {m}^{3} [/tex]
[tex]s \: a \: \: = (3 \times 7) + (4 \times 7) + (5 \times 7)[/tex]
[tex]s \: a \: \: = 21 + 28 + 35[/tex]
[tex]s \: a \: \: = 84 \: \: \: {m}^{2} [/tex]
