The following nine steps include detailed instructions that explain how to create the custom function AreaCircle(Radius), which you can use to calculate the area of a circle. You have to pass the radius as a number, a calculated expression, or a cell reference as the argument for the function.
Press Alt+F11 to open the Visual Basic Editor (in all Excel versions).
In Excel 2003 and previous versions, you can select Tools/Macro/Visual Basic Editor, and in the Excel 2010 and Excel 2007, you can click Visual Basic on the Developer tab.
Like other typical windows in Windows, the Visual Basic Editor has a title bar, a menu bar, and toolbars. On the left side, you can see two subwindows: the Project Explorer window and the Properties ...