The Arc 3Points tool creates a circular arc in the current work plane by entering three points that lie on the circumference; the center and radius are determined from these three points. It uses the Draft Linestyle set on the Draft Tray.
Use the Draft Arc tool to create a circular arc by specifying the center, the radius, and the start and end angles. To draw an elliptical arc use Draft Ellipse. You can also approximate a circular arc by using the Draft BSpline, Draft BezCurve, and Draft CubicBezCurve tools.
Arc defined by three points lying on a circumference
- Press the Draft Arc 3Points button, or press A then T keys.
- Click a first point on the 3D view, or type a coordinate and press the add point button.
- Click a second point on the 3D view, or type a coordinate and press the add point button.
- Click a third point in the 3D view, or type a coordinate and press the add point button.
- The arc will be created after the third point is given.
- Press X, Y or Z after one point to constrain the following point on the given axis.
- To enter coordinates manually, simply enter the numbers, then press Enter between each X, Y and Z component.
- You can press the add point button when you have entered the desired values to insert the point.
- Press R or click the checkbox to toggle relative mode. If relative mode is on, the coordinates of the following point are relative to the previous one; if not, they are absolute, taken from the origin
(0, 0, 0).
- Hold Shift while drawing to constrain your next point horizontally or vertically in relation to the previous one.
- Press Esc or the Close button to abort the current command.
An Arc object shares all properties from a Draft Circle, but some properties only make sense for the circle. See Draft Arc for more information.
See also: Draft API and FreeCAD Scripting Basics.
There is no specific function to create an arc by three points.
To create an arc use the same function to create circles, with additional arguments. See the information in Draft Arc and Draft Circle.
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