|Class 8 Maths Mensuration||Volume of Cube, Cuboids and Cylinder|
Volume of Cube, Cuboids and Cylinder
Amount of space occupied by a three dimensional object is called its volume.
The cube is a special case of a cuboid, where l = b = h.
Hence, volume of cube = l * l * l = l3
Problem: Find the volume of cube if its each side is of length is 5 cm.
Given, l = b = h = 5 cm
volume of cube = l * b * h = 5 * 5 * 5 = 125 cm3
Volume of a cuboid is equal to the product of length, breadth and height of the cuboid.
Let l is the length, b is the breadth and h is the height of the cuboid.
Then volume of cuboid = l * b * h
Problem: Find the height of a cuboid whose base area is 180 cm2 and volume is 900 cm3?
Given: Base area of cuboid = 180 cm2 and Volume of cuboid = 900 cm3
We know that, Volume of cuboid = l * b * h
=> 900 = 180 * h [Base area = l * b = 180 (given)]
=> h = 900/180
=> h = 5 m
Hence, the height of cuboid is 5 m.
Let r is the radius of circular region and h is the height of cylinder.
Then volume of cylinder = πr2 * h = πr2h
Problem: Find the height of the cylinder whose volume if 1.54 m3 and diameter of the base is 140 cm.
Given: Volume of cylinder = 1.54 m3 and Diameter of cylinder = 140 cm
Radius (r) = 140/2 = 70 cm
Volume of cylinder = πr2 h
=> 1.54 = 22/7 * 0.7 * 0.7 * h
=> 1.54 = 22 * 0.1 * 0.7 * h
=> 1.54 = 1.54 * h
=> h = 1.54/1.54
=> h = 1 m
Hence, the height of the cylinder is 1 m.