Question

Find the volume of a cube whose surface is 486 cm square

Answer 1

Hi friend
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Your answer
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Total surface area of a cube given = 486 cm²

Now,
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6 × (side)² = 486

=> (side)² = 486/6

=> (side)² = 81

=> side = √81

=> side = 9 cm

Then,
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Volume = side × side × side

=> ( 9 × 9 × 9) cm³

=> 729 cm³

HOPE IT HELPS

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✯ BRAINLY STAR ✯

Answer 2

$\textbf{\huge\underline{\underline\red{Solution} : - }} \\ \\\textbf{\underline{\red{given} : - }} \: \: \bold{total \: surface \: area\: of \: cube \: is \:} \\ \bold{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 486 \: {cm}^{2} } \\ \\ \textbf{\underline{\red{to \: find} : - } } \: \bold{volume \: of \: cube.} \\ \\ \textbf{\underline{\red{formula} : - }} \: \\ \\ \bold \purple{total \: surface \: area\: of \: cube \: = 6 {a}^{2} } \\ \\ \bold \purple{ \: volume \: of \: cube \: = {a}^{3} } \\ \\ \bold\red{where \: \: \purple{a} \: \: is \: edge \:of \: cube. } \\ \\ \bold{\underline \red{now}} \\ \\ = > \bold \purple{ \: total \: surface \: area \: of \: cube \: = 6 {a}^{2} } \\ \\ = > \bold \purple{486= 6 {a}^{2} } \\ i.e\\ = > \bold \purple{6 {a}^{2} = 486} \\ \\ = > \bold \purple{ {a}^{2} = \frac{486}{6} } \\ \\ = > \bold \purple{{a}^{2} = 81}\\ \\ = > \bold \purple{{a} = \sqrt{81} }\\ \\ = > \bold \purple{{a} = \: 9 \:cm} \\ \\ \bold{\underline \red{now}} \\ \\ = > \bold \purple{ \: volume \: of \: cube \: = {a}^{3} } \\ \\ = > \bold \purple{ \: volume \: of \: cube \: = {9}^{3} } \\ \\ = > \bold \purple{ \: vomeu \: of \: cube \: = 729 \: {cm}^{3} } \\ \\ \fbox{\bold \red{ hence \: volume \: of \: cube \: is \: 729 \: {cm}^{3} }}$