Find the area of the square whose side is equal to 7.5 cm.

Hint: Let us assume the length of the given square is equal to 7.5 cm. Let us assume this as equation (1). We know that if the length of the side of a square is equal to x, then the area of the square is equal to \[{{x}^{2}}\]. Let us assume the area of the square is equal to A. So, now we have to find the square of value of x which is obtained from equation (1). Let us assume this as equation (2). Now from equation (2), we can get the value of the area of the square whose side is equal to 7.5 cm.

Complete step-by-step answer:
Before solving the question, we should know that if the length of the side of a square is equal to x, then the area of the square is equal to \[{{x}^{2}}\].
From the question, it was given that the length of the side of the square is equal to 7.5 cm. Let us assume the side of the square is equal to x. Then we get
\[\Rightarrow x=7.5....(1)\]

We know that if the length of the side of a square is equal to x, then the area of the square is equal to \[{{x}^{2}}\]. Let us assume the area of the square is equal to A.
\[\Rightarrow A={{x}^{2}}.....(2)\]
Now let us substitute equation (1) in equation (2), we get
\[\begin{align}
  & \Rightarrow A={{(7.5)}^{2}} \\
 & \Rightarrow A=56.32.....(3) \\
\end{align}\]
So, from equation (3) it is clear that the area of the square whose side is equal to 7.5 cm is 56.32 sq.cm.

Note: Some students may have a misconception that if the diagonal of a square is equal to x, then the area of the square is equal to \[{{x}^{2}}\]. This misconception will get the final answer affected. So, this misconception should be avoided.