It is a wrong equation that a square equals a circle, because a square and a circle are two different figures, which are not comparable in mathematics. A square is a quadrilateral with four right angles and four equal sides, while a circle is a curved figure with the characteristics of infinity and no angle. Therefore, there are obvious differences between squares and circles in essence, and they cannot be directly compared. Mathematically, if we want to compare the area or volume of two figures, we need to use corresponding formulas and methods, and we can't simply equate them. In a word, it is a wrong equation that a square equals a circle, because they are two different figures and cannot be compared.