Question

${\large{\pmb{\sf{Hello, \: viewers!!!}}}}$

How to know that where we have to apply these given formula according to the question(s)!?

➝ Formula to calculate the lateral surface area of cuboid.

➝ Formula to calculate the surface area of cuboid.

Any application regards these!? For example, “ A plastic box 1.5 m long, 1.25 m wide and 650 cm deep is to be made. It is open at the top. Determine the area of sheet required for making the box!?

As here we have applied " 2(bh+hl) + lb " as our formula instead of 2(lb+bh+hl) because the box is opened!

But why we apply this formula!? Why not lateral surface area of cuboid formula!?

• Also write down the differences between lateral surface area and surface area.

​

Answer 1

༒࿐៚ Answer ༒࿐៚

➝ Formula to calculate the lateral Surface are of cuboid :- 2h ( l + b ).

Where l = length. b = breadth and h = height.

➝Formula to calculate the Surface area of Cuboid :-2( lb + bh + hl ).

Where l = length, b = breadth and h = height.

➝We have applied " 2 ( bh + hl ) + lb " as our formula instead of 2( lb + bh + hl ) because the box is opened. We apply this formula because they both are same if we open the Bracket then we get the same formula i.e 2 ( lb + bh + hl ).

Differences between lateral surface area and surface area:-

Lateral Surface : it includes the area of all the surface excluding the top and bottom.

Surface Area :- it includes the area of surfaces of the object including the bases.

Hope it will help u.

Answer 2

Q) Formula to calculate the lateral surface area of cuboid.

⇒When we are given with the sides of the lateral sides of cuboid we will use the lateral surface area formula.

$\sf\;\boxed{\sf\;Lateral\;surface\;area_{cuboid}=2heigth(length\times breadth)}$

Q)Formula to calculate the surface area of cuboid.

⇒When we are given with the all sides of the cuboid we use surface area formula

$\sf\;\boxed{\sf\;\;surface\;area_{cuboid}=2(length\times breath+breadth\times heigth+heigth\times length)}$

Q)A plastic box 1.5 m long, 1.25 m wide and 650 cm deep is to be made. It is open at the top. Determine the area of sheet required for making the box?

⇒in this question we have to find the area of sheet required to make the box ,but here we will apply the formula fro Surface area but we will subtract the area of top ,as we can cover the top of the box .

Q)Difference between lateral surface area and surface area

⇒ SURFACE AREA

→We find the area of all sides

→Formula=2(lb+bh+hl)

Lateral surface area

→We find area of lateral sides

→Formula=2h(l+b)

I hope you are crystal clear with my answer.

:)