Question

the total surface area of a cuboid is 85cm^2 and its lateral surface is 63cm^2 find the area of its base

Answer 1

Solution:-
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T.S.A. of cuboid - L.S.A. of cuboid = Area of top + Area of base

It is given that T.S.A. = 85 cm² and L.S.A. = 63 cm²

So, 2(lb + bh + hl) - 2h(I + b) = 85 - 63

2lb + 2bh + 2hl - 2hl - 2bh = 22

2lb = 22

lb = 11 cm²

∴ Area of base is 11 cm².

[Answer:- Area of base is 11 cm²].
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Answer 2

Answer:

11 cm sq.

Step-by-step explanation:

TSA = 85 cm sq.

LSA = 63 cm sq.

area of base = tsa - (lsa)/2

because , tsa = top+base+ 4 sides

                 lsa = 4 sides (no top and bottom )

           we need to find the base area ie. we need to find only the area of base. If we subtract the tsa &lsa we get the area of top and bottom of the cuboid. As area of top and base are equal we can divide it by 2 to obtain the area of  base  

= 85-63 = 22/2 = 11 cm sq.