Icse class 7th surface area and volume

1. SURFACE AREA AND VOLUME
by-
PavanKumar Magar
By Pavankumar Magar
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2. By Pavankumar Magar
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3. SURFACE AREA OF CUBOID
Total Surface Area Of cuboid =
2(lb+bh +lh)
Lateral Surface of Cuboid:
2(l+b)h
By Pavankumar Magar
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4. EXAMPLE
 Rafiq uses plywood and sunmica for a cupboard that he has to
make. The dimension of the cupboard l × b × h is 3 × 2 × 5. The
exterior of the cupboard, excluding the top and bottom has to be
covered with sunmica.
 Find
 Area of plywood used.
 Area of sunmica used.
 Amount spend on plywood and sunmica if the cost of plywood
and sunmica is Rs. 60 per sq feet and Rs. 12 per sq feet,
respectively.
By Pavankumar Magar
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5. Solution:
The dimension of the cupboard are l = 3 feet, b = 2 feet and h = 5 feet.
Therefore, the total plywood used to make the cupboard
= total surface area of the cupboard
= 2lb + 2bh + 2lh
= 2 × 3 × 2 + 2 × 2 × 5 + 2 × 3 × 5
= 12 + 20 + 30
= 62 sq feet
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By Pavankumar Magar

6. Sunmica is used to cover the exterior of the cupboard, excluding
the top and bottom surfaces
Therefore, the total sunmica used to cover the exterior of the
cupboard
= lateral surface area of the cupboard
= 2lh + 2bh
= 2 × 3 × 5 + 2 × 2 × 5
= 30 + 20
= 50 sq feet
The cost of plywood per sq feet = Rs. 60
Therefore the total cost of plywood = 62 × Rs. 60 = Rs. 3720
The cost of sunmica per sq feet = Rs. 12
Therefore, the total cost sunmica = 50 × Rs. 12 = Rs. 600
Therefore, the total cost of the cupboard = Rs. 3720 + Rs. 600 =
Rs. 4320By Pavankumar Magar
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7. VOLUME OF CUBOID
volume of cuboid – l*b*h
By Pavankumar Magar
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8. By Pavankumar Magar
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9. SURFACE AREA OF CUBE
Total surface area of cube- 6(side)²
Lateral surface area of cube-4(side)²
By Pavankumar Magar
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10. EXAMPLE
 A cube shaped box having side 25 cm as shown in the figure (A)
is covered using marble papers as shown in the figure (B). Red
coloured paper is used for the sides and blue coloured paper for
the top and bottom. How much red coloured paper is used?How
much blue coloued paper is used?
By Pavankumar Magar
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11.  Solution:
 The red coloured paper covers the lateral surface area of the cubical
box.
 Thus, the quantity of the red coloured paper = area of the lateral surface
 = 4 × l square
 = 4 × 252 = 2500 sq cm
 The blue coloure paper covers the top and bottom surfaces of the cubical
box.
 The Quantity of the blue coloured paper used = 2 × l square
 = 2 × 25 square = 1250 sq cm

By Pavankumar Magar
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12. VOLUME OF CUBE
Volume of cube=(side)³
By Pavankumar Magar
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13. By Pavankumar Magar
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