Chart Components > Mathcad Chart Window > Formatting Your Chart > Chart Look and Feel > To Add and Format a Legend
  
To Add and Format a Legend
1. Click the Chart icon , and then click the Legend tab.
2. Select the Chart Legend checkbox. A legend appears automatically in the chart, populated with the default trace color, number, and location.
3. Specify the Location, Font, Color, Styles, Size, and Columns.
4. Select the Border checkbox and specify the Color, Style, Thickness, and Corners.
5. Select the Background checkbox and specify the Fill and Opacity.
For example, in the chart below:
Legend location is Top, Left
Border color is purple, and its corners are set to 3px
Background color is yellow and its opacity is set to 70 %