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The surface area of a cuboid formed by joining face to face 3 cubes of side x is 3 times the surface area of a cube of side x. - Mathematics

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प्रश्न

The surface area of a cuboid formed by joining face to face 3 cubes of side x is 3 times the surface area of a cube of side x.

विकल्प

  • True

  • False

MCQ
सत्य या असत्य
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उत्तर

This statement is False.

Explanation:

Three cubes having side x are joined face-to-face, then the cuboid so formed has the same height and breadth as the cubes but its length will be thrice that of the cubes.

Hence, the length, breadth and height of the cuboid so formed are 3x, x and x, respectively.

Then, its surface area = 2(lb + bh + hl)

= 2(3x × x + x × x + x × 3x )

= 2(3x2 + x2 + 3x2)

= 2 × 7x2 

= 14x2

Now, the surface area of the cube of side x = 6 (Side)2 = 6x2.

Hence, the statement is false.

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अध्याय 11: Mensuration - Exercise [पृष्ठ ३५१]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 8
अध्याय 11 Mensuration
Exercise | Q 55. | पृष्ठ ३५१

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