Draw a circular arc defined by three points in the circumference.
Parameters
----------
points: list of Base::Vector3
A list that must be three points.
placement: Base::Placement, optional
It defaults to `None`.
It is a placement, comprised of a `Base` (`Base::Vector3`),
and a `Rotation` (`Base::Rotation`).
If it exists it moves the center of the new object to the point
indicated by `placement.Base`, while `placement.Rotation`
is ignored so that the arc keeps the same orientation
with which it was created.
If both `support` and `placement` are given,
`placement.Base` is used for the `AttachmentOffset.Base`,
and again `placement.Rotation` is ignored.
face: bool, optional
It defaults to `False`.
If it is `True` it will create a face in the closed arc.
Otherwise only the circumference edge will be shown.
support: App::PropertyLinkSubList, optional
It defaults to `None`.
It is a list containing tuples to define the attachment
of the new object.
A tuple in the list needs two elements;
the first is an external object, and the second is another tuple
with the names of sub-elements on that external object
likes vertices or faces.
::
support = [(obj, ("Face1"))]
support = [(obj, ("Vertex1", "Vertex5", "Vertex8"))]
This parameter sets the `Support` property but it only really affects
the position of the new object when the `map_mode`
is set to other than `'Deactivated'`.
map_mode: str, optional
It defaults to `'Deactivated'`.
It defines the type of `'MapMode'` of the new object.
This parameter only works when a `support` is also provided.
Example: place the new object on a face or another object.
::
support = [(obj, ("Face1"))]
map_mode = 'FlatFace'
Example: place the new object on a plane created by three vertices
of an object.
::
support = [(obj, ("Vertex1", "Vertex5", "Vertex8"))]
map_mode = 'ThreePointsPlane'
primitive: bool, optional
It defaults to `False`. If it is `True`, it will create a Part
primitive instead of a Draft object.
In this case, `placement`, `face`, `support`, and `map_mode`
are ignored.
Returns
-------
Part::Part2DObject or Part::Feature
The new arc object.
Normally it returns a parametric Draft object (`Part::Part2DObject`).
If `primitive` is `True`, it returns a basic `Part::Feature`.
None
Returns `None` if there is a problem and the object cannot be created.
