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प्रश्न
The surface area of a cuboid formed by joining two cubes of side a face to face is ______.
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उत्तर
The surface area of a cuboid formed by joining two cubes of side a face to face is 10a2.
Explanation:
We have, two cubes of side a.
These two cubes are joined face-to-face, then the resultant solid figure is a cuboid which has same breadth and height as the joined cubes has length twice of the length of a cube,
i.e. l = 2a, b = a and h = a
Thus, the total surface area of the cuboid = 2(lb + bh + hI)
= 2(2a × a + a × a + a × 2a)
= 2(2a2 + a2 + 2a2)
= 2 × 5a2
= 10a2
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