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# If the volume of a cube is 729 cu. cm. what is the length of its diagonal?

 A) $$\Large 9\sqrt{2} cm$$ B) $$\Large 9\sqrt{3} cm$$ C) 18 cm D) $$\Large 18\sqrt{3} cm$$

 B) $$\Large 9\sqrt{3} cm$$

Volume of cube = $$\Large Side^{3}$$

Therefore, 729 = $$\Large a^{3}$$ => a = 9 cm

Therefore, Diagonal of cube = $$\Large Side \times \sqrt{3}$$

$$\Large 9 \times \sqrt{3}$$

$$\Large 9\sqrt{3}$$ cm .

Part of solved Volume and surface area questions and answers : >> Elementary Mathematics >> Volume and surface area

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