For 2-D polygon element in the EJS, you need to provide x[n],y[n] arrays to represent the X,Y coordinate for n points.

If the polygon is not closed (you can change the property), then ejs will draw all the points and draw lines between i and i+1 points except the last one.
If the polygon is closed, then it will draw another line connect the last point to the first one. When it is a closed polygon, you can set [u]color[/u] to fill the inside of the polygon.