From FreeCAD Documentation
- There are several ways to invoke the tool:
- The cursor changes to a cross with the tool icon.
- Pick the center of the major radius of the arc (labelled 1 in the image above).
- Pick the vertex of the arc (labelled 2 in the image above), this also defines its major radius.
- Pick the start point of the arc (labelled 3 or 4 in the image above), this also defines its curvature.
- Pick the endpoint of the arc (labelled 3 or 4 in the image above).
- The arc of hyperbola is created, including a set of internal geometry.
- If the tool runs in continue mode:
- Optionally keep creating arcs.
- To finish, right-click or press Esc, or start another geometry or constraint creation tool.