Question

find the total surface are and lateral surface area of a chak whose height , length and breadth are 25 cm,20cmand 15 cm respectively ​

Answer 1

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Given that l=20cm, b=12cm, h=9cm

∴T.S.A=2(lb+bh+lh)

=2[(20×12)+(12×9)+(20×9)]

=2(240+108+180)

=2×528

∴T.S.A=1056cm

Answer 2

Given :

• Length = 25 cm

• Breadth = 20 cm

• Height = 15 cm

To find :

• Curved surface area of the cuboid.

• Total surface area of the Cuboid.

Solution :

To find the Curved surface area of the Cuboid :

Using the formula for curved surface of a Cuboid and substituting the values in it , we get :-

$\underline{:\implies \bf{CSA = 2(l + b)h}}$

Where :-

• CSA = Curved surface area of the Cuboid.

• l = Length of the Cuboid.

• b = Breadth of the Cuboid.

• h = Height of the cuboid.

$:\implies \bf{CSA = 2 \times (25 + 20) \times 15}$

$:\implies \bf{CSA = 2 \times 45 \times 15}$

$:\implies \bf{CSA = 1350}$

$\underline{\therefore \bf{CSA = 1350\:cm^{2}}}$

Hence, the Curved surface area of the Cuboid is 1350 cm².

To find the total surface area of the cuboid :-

Using the formula for total surface area of a Cuboid and substituting the values in it , we get :

$\underline{:\implies \bf{TSA = 2(lb + lh + bh)}}$

Where :-

• TSA = Total surface area of the Cuboid.

• l = Length of the Cuboid.

• b = Breadth of the Cuboid.

• h = Height of the cuboid.

$:\implies \bf{TSA = 2(25 \times 20 + 25 \times 15 + 20 \times 15)}$

$:\implies \bf{TSA = 2(500 + 375 + 300)}$

$:\implies \bf{TSA = 2(1175)}$

$:\implies \bf{TSA = 2350}$

$\underline{\therefore \bf{TSA = 2350\:cm^{2}}}$

Hence, the total surface area of the cuboid is 2350 cm².