Page 180 - Start Up Mathematics_5

Volume of a cuboid = Length × Breadth × Height

Length of a cuboid = Volume
Breadth × Height

Breadth of a cuboid = Volume
Length × Height

Volume
Height of a cuboid = Length × Breadth

Since, a cube is a cuboid with all sides equal (Length = Breadth = Height), its volume is the
product of all its sides.

Volume of a cube = Side × Side × Side = (Side) 3

Before solving problems on volume, let’s quickly recall the unit conversion formulas.
1 m = 100 cm , 1 kg = 1,000 g Remember

1 dm = 10 cm , 1 g = 1,000 mg Change all dimensions
1 km = 1,000 m , 1 kL = 1,000 L into the same unit before
calculating the volume.
1 cm = 10 mm , 1 L = 1,000 mL

Example 16: Find the volume of a cuboidal box whose length is 20 cm, breadth is 14 cm
and height is 8 cm.

Solution: Length = 20 cm, Breadth = 14 cm, Height = 8 cm

Volume = Length × Breadth × Height
= 20 cm × 14 cm × 8 cm
= 2,240 cm 3

Example 17: Find the volume of a cube whose side is 7 cm.

Solution: Side of the cube = 7 cm
Volume of a cube = Side × Side × Side
= 7 cm × 7 cm × 7 cm

= 343 cm 3

Example 18: The volume of a box is 240 m . If the length and breadth of the box are 8 m
3
and 6 m respectively, find the height of the box.

Solution: Volume of the box = 240 m 3
Length = 8 m, Breadth = 6 m, Height = ?

Height = Volume = 240 m 3 = 240 m 3 = 5 m
Length × Breadth 8 m × 6 m 48 m 2

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