I want to draw 2D closed shapes (such as a triangle, a circle, etc) with which a single color is filled, but I could not find a suitable class to finish this task after trying all the provided chart types. 
My first attempt is the Line series, but it could not be filled with colors.
My second attempt is the grid/mesh/triangle surface series with DrawFlat set to true, but it didn't work since the thickness of a 2D shape is 0, thus I couldn't see it in the chart.
Finally I tried the shape class, and sadly it only supports limited pre-defined shapes. But I need to draw irregular shapes - with arbitrary outlines.
Are there any suitable classes that can satisfy my requirements? Thank you!