A cube is a three-dimensional shape with equal width, height, and length measurements. A cube has six square faces, and each face will have a side of equal length. Finding the volume of a cube is sometimes very much essential. Generally to find the volume of a cuboid we needed to multiply its length × width × height. In this article, we will explore the formula used to calculate the volume of a cube. The student will also gain a conceptual understanding for volume of cube formula and appropriate units to use. Let us start learning!
Volume of a cube formula
What is Cube?
What do children’s building blocks, a milk crate, and dice have all in common? Also, what is unique about the shape of their sides? All such objects are the example of a perfect cube. A cube is a unique three-dimensional shape that has squares for all six of its sides.
The volume of a cube will define the number of cubic units, that cube will occupy. A cube has a solid three-dimensional figure, which has 6 square faces or sides. Many objects like water tank, ludo dice etc are found in the shape of a cube.
The formula for Volume of Cube:
We can easily find the volume of the cube by knowing the length of its one edge. Suppose, the length of the edges of the cube is ‘a’. Then the V will be the product of length, height, and width. Its derivation is given below.
Derivation for Volume of a Cube:
The volume of an object is defined as the amount of space that a solid occupies. As we know that a cube is a 3-dimensional object with all equal sides i.e. length, breadth, and height. Cube volume formula derivation is as follows:
- Consider a square piece of paper.
- The area that square sheet will take up will be its surface area i.e. its length X breadth.
- As the square will have equal length and breadth, so the surface area will be a².
- Now, a simple cube can be made by stacking multiple square sheets on top of each other to get height as a unit.
- Hence it can be concluded that the overall area covered by the cube will be the area of the base multiplied by the height.
- So, Volume of Cube,
V = a² X a
i.e. V = a³
Where,
V | Volume of cube |
a | Length of one side |
Solved Examples
Q.1: Find the volume of a cube with sides of length 7 cm.
Solution:
Given, the length of the sides of the cube is 7cm.
We know, V = a³
Therefore, Volume, V = (7 cm)³
So, Volume VÂ = 343 cubic cm.
Q.2: Find the length of the edges of the cube, if its volume is equal to 125 cubic cm.
Solution:
Given, Volume of the cube = 125 cubic cm.
Let the length of the edges is a.
We know,
The volume V = a³
Substituting the value, we get,
V = a³
Or
a = \(\sqrt[3]{V}\)
= \(\sqrt[3]{125}\)
= 5 cm
Therefore, the length of the cube is 5 cm.
I get a different answer for first example.
I got Q1 as 20.5
median 23 and
Q3 26