Click the chart to select it.
In the Format sidebar, then do any of the following:
Change the shape of data symbols: Click the pop-up menu below Data Symbols and choose a symbol, or choose None to remove symbols for this data series.
Change the color of data symbols: Click the pop-up menu below Fill and choose an option. Choose Use Series Stroke Color to revert to presets.
Change the outline of data symbols: Click the pop-up menus below Stroke, and change the style, color, and weight.
Add a line connecting data symbols: Click the pop-up menu next to Connection Line and choose Straight or Curved. Use the pop-up menus below to change the style, color, and weight of the connecting line.
Add a shadow: Select the Shadow checkbox to add a shadow and adjust its blur distance, offset, opacity, angle, and color.
You can change the shape of the grid on a radar chart and choose whether the series have a fill or stroke.