find the total surface area and lateral surface area of cuboid whose length breadth and hight is 20cm 15cm and 18cm.
Answers
Explanation:
As we know the, the total surface area of cuboid (TSA)=
\sf{ = 2(length \times breadth + breadth \times height + heigh \times length}=2(length×breadth+breadth×height+heigh×length
Now, putting the values, we get,
\sf{\implies \: TSA = 2(20 \times 15 + 15 \times 18 + 18 \times 20}⟹TSA=2(20×15+15×18+18×20
\sf{\implies TSA = 2(300 + 270 + 360}⟹TSA=2(300+270+360
\sf{\implies TSA = 2 \times 930}⟹TSA=2×930
\sf{\implies TSA = 1860}⟹TSA=1860
Now,
The lateral surface area of the cuboid (LSA)=
\sf{\implies 2 \times height( length+breadth)}⟹2×height(length+breadth)
Now, putting the values, we get,
\sf{\implies LSA = \: 2 \times 18(20 + 15)}⟹LSA=2×18(20+15)
\sf{\implies LSA = 2 \times 18 \times 35 }⟹LSA=2×18×35
\sf{\implies LSA = 1260}⟹LSA=1260
Hence, the total surface area and the lateral surface area of the cuboid are 1860cm² and 1260cm².
Answer
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=1056cm²