Q1 of 44 Page 14

Three cubes each of side 5 cm are joined end to end to form a cuboid. Find the surface area of the resulting cuboid.



Length of each side of cube = 5cm


According to question,


Three cubes are joined end to end to form a cuboid


So, the length of the resulting cuboid = 5 + 5 + 5 = 15cm


But, the breadth and height will remain the same


So, Breadth = 5cm


and height = 5cm


Surface Area of the Cuboid


= 2(Length × Breadth + Breadth × Height + Height × Length)


= 2(lb + bh + hl)


= 2(15×5 + 5×5 + 5×15)


= 2(75 + 25 + 75)


= 2(175)


= 350cm2


Hence, the surface area of cuboid is 350cm2.


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Find:

(i) the lateral surface,


(ii) the whole surface, and


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[Take π=3.14]