How to insert an equation in Excel

Excel is primarily used for its spreadsheet functions but it also supports several textual functions.  When evaluating an equation, for example, the area of a circle, you can do so by typing the formula in the cell using the equal sign (=). The problem arises when you want to include the equation itself. It becomes a complex process to include the Pi character or numerators and denominators within the cell. To solve this problem, Excel has some preset equations that can be used.