Polygon

Polygon (Triangle)

Each point is made of [x,y] parameters.The following makes a triangle shape:

polygon(points=[[0,0],[100,0],[0,100]]);

linear_extrude(height=100)
polygon(points=[[0,0],[100,0],[0,100]]);

linear_extrude(height=100, twist=360)
polygon(points=[[0,0],[100,0],[0,100]]);

There are other 2D shapes we can create and extrude (square, circle, ellipse).
Notice that there is no semicolon following the linear_extrude command. This is because commands relate to the following object. If we put a semicolon there it would end the thought and relate to nothing.