Question

Total surface area of a cube of 2- centimetre side is
A. \[20c{{m}^{2}}\]
B. \[24c{{m}^{2}}\]
C. \[25c{{m}^{2}}\]
D. \[30c{{m}^{2}}\]

Answer 1

Hint: In order to find the answer of the question that is total surface area of a cube of 2-centimetre side is you should know the formula that is the total surface area of a cube \[=6{{a}^{2}}\] where \[a\] is the length of the side of each edge of the cube. Since all sides of a cube are equal, \[a\] is just the length of one side of a cube.

Complete step by step solution:
According to the question, the length of the side of the cube is 2-centimetre, where a cube is a 3-D solid shape, which has 6 sides. A cube is one of the simplest shapes in the three-dimensional space. Sometimes, the shape cube is considered as “cubic”. We can also say that a cube is considered as a block, where all the length, breadth and height are the same. Along with that, it has 8 vertices and 12 edges such that 3 edges meet at one vertex point. Since the cube is a 3D shape, the two important parameters used to measure the cube are surface area and volume.
And as per given in the question, we have to find the total surface area of the cube here:
Therefore, apply the formula that is the total surface area of a cube \[=6{{a}^{2}}\] where \[a\] is the length of the side of each edge of the cube.
According to the question,
\[a=2\] centimetre
Now substitute this value of \[a\] in the formula of total surface area of cube we get:
Total surface area of cube\[=6{{\left( 2 \right)}^{2}}\]
\[\Rightarrow \]Total surface area of cube\[=6\times 4\]
\[\Rightarrow \]Total surface area of cube\[=24c{{m}^{2}}\]
Hence the Total surface area of a cube of 2- centimetre side is \[24c{{m}^{2}}\] which is option B.

So, the correct answer is “Option B”.

Note: Students can go wrong by applying the wrong formula while calculating the surface area of cube, they use \[{{a}^{2}}\]which is completely wrong as \[{{a}^{2}}\]is the area of the square and not the surface area of the cube. Key point is to remember the formula that is the total surface area of a cube \[=6{{a}^{2}}\] where \[a\] is the length of the side of each edge of the cube. Since all sides of a cube are equal, \[a\] is just the length of one side of a cube.