Draw Polygon Perpendicular to Cplane


I noticed that every time I make a polygon from a point, the geometry is at an angle. I would like to draw a rectangle with two edges perpendicular to the c plane. Does anyone know how to do this?

Maybe you have “Draw Full Names” off…

2021-06-09 17_57_28-Grasshopper - unnamed
“P” input of polygon and rectangle components is not “Point” but “Plane”!
If you connect there a point it will be implicitly converted to a WorldXY plane with origin on your point.

To have a vertical plane use XZ or YZ plane components:
2021-06-09 18_06_32-Grasshopper - unnamed