Though this technique can work, and work for multiple programs, I don't use it often I used it to type the π and Δ symbols above. In it you can find a wealth of characters that you can copy onto the clipboard and paste into whatever program you're typing in. You can find it by pressing the Windows button and searching for character map - and then the window on the right will pop up. In Windows, you can find the old Character Map - a program I've seen since I used Windows 3.1 growing up.
The lazy thing to do is just type pi, or delta, but there are a handful of ways to insert these symbols into a document. Other Greek letters are useful too, such as Δ for change in.
When typing up notes, worksheets, and assignments, I often find myself needing to type some special mathematical symbols, such as π.
