The line chart can be a polar plot such as the one shown in the following figure:
Each point has two data values: x (angle) and y (radius). Each point is visualized as a point on a line.
A polar line series or each point in the series can be assigned a border, fill effect, and a depth for the line. You can also specify whether the line is closed. Assigning null for a border or fill effect indicates that the property is unset. Depth is measured relative to plot area depth (0 = no depth, 1 = full depth of plot area).
For more information on the line series object in the API, refer to the PolarLineSeries class.