Question

find the total surface area and lateral surface area of cuboid whose length breadth and hight is 20cm 15cm and 18cm.​

Answer 1

Answer :

• Total surface area of cuboid is 1860cm²
• Lateral surface area of cuboid is 1260cm²

Given :

• Length is 20cm
• Breadth is 15cm
• Height is 18cm

To find :

• Total surface area of cuboid
• Lateral surface area of cuboid

Solution :

As we know that ,

• Total surface area of cuboid = 2(lb + bh + lh)

where , l is length 20cm , b is breadth 15cm and h is height 18cm

⇢ 2(lb + bh + lh)

⇢ 2(20×15+ 15×18 + 20×18)

⇢ 2(300 + 270 + 360)

⇢ 2(930)

⇢ 1860cm²

Total surface area of cuboid is 1860cm²

As we know that,

• Lateral surface area of cuboid = 2h(l + b)

where , l is length 20cm , b is breadth 15cm and h is height 18cm

⇢ 2h(l + b)

⇢ 2 × 18(20 + 15)

⇢ 36(20 + 15)

⇢ 36(35)

⇢ 1260 cm²

Lateral surface area of cuboid is 1260cm²

Hence ,

• Total surface area of cuboid is 1860cm²
• Lateral surface area of cuboid is 1260cm²

Answer 2

$\huge\underline\mathfrak\color{plum}Given$

• Length of the cuboid = 20cm
• Breadth of the cuboid = 15 cm
• Height of the cuboid = 18 cm

$\huge\underline\mathfrak\color{plum}To \: Find$

• The total surface area and lateral surface area of cuboid.

$\huge\underline\mathfrak\color{plum}Solution$

As we know the, the total surface area of cuboid (TSA)=

$\sf{ = 2(length \times breadth + breadth \times height + heigh \times length}$

Now, putting the values, we get,

$\sf{\implies \: TSA = 2(20 \times 15 + 15 \times 18 + 18 \times 20}$

$\sf{\implies TSA = 2(300 + 270 + 360}$

$\sf{\implies TSA = 2 \times 930}$

$\sf{\implies TSA = 1860</u></strong><strong><u>}$

Now,

The lateral surface area of the cuboid (LSA)=

$\sf{\implies 2 \times height( length+breadth)}$

Now, putting the values, we get,

$\sf{\implies LSA = \: 2 \times 18(20 + 15)}$

$\sf{\implies LSA = 2 \times 18 \times 35 }$

$\sf{\implies LSA = 1260</u></strong><strong><u>}$

Hence, the total surface area and the lateral surface area of the cuboid are 1860cm² and 1260cm².