Mathematics
The volume of a cube is 729 cm3. Find its surface area and the length of a diagonal.
Mensuration
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Answer
Given,
Volume of a cube = 729 cm3.
By formula,
Volume of a cube = (side)3
∴ (side)3 = 729
⇒ (side)3 = (9)3
⇒ side = 9 cm
By formula,
Surface area of cube = 6(side)2
= 6 × (9)2
= 6 × 9 × 9
= 486 cm2.
So the length of a diagonal = × side
= × 9
= 1.732 × 9
= 15.57 cm.
Hence, surface area = 486 cm2 and length of diagonal = 15.57 cm.
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