Legends are useful for charts with multiple groups of data.
To show a legend in your chart:
Double-click the chart with your left mouse button.
Right-click the chart once. A menu will appear.
Click Chart Designer. The Chart Designer window will open.
In the box on the left, click Legend. Here, you can click a tab for further options:
Location: Allows you to specify the location of the legend in your chart. To show the legend, check off Visible. (If Visible is NOT checked off, then the legend will NOT appear.)
Backdrop: Allows you to change the background color and border of your legend. In the Fill section, you can specify the background fill style. Select a Gradient or Brush (pattern), and the fill colors. In the Frame section, you can add a border to your legend. Select a Style (Single Line, Double Line, etc.) and Color. In the Shadow section, you can add a shadow behind your legend. Select Drop from the Style box.
Picture: Allows you to place an image behind your legend. Click Browse to select an image file.
Font: Allows you to change the font attributes of your legend text. Select a Font (Arial, Verdana, etc.), Font Style (Regular, Bold, Italic), Size, Effects (Strikeout, Underline), and Color.
When you are done, click Apply, and then OK.