Translations:Sketcher Micro Tutorial - Constraint Practices/33/en

From FreeCAD Documentation
5.6. Select one bottom corner point (a), then the top corner point that is diagonally opposite, and then the origin of the sketch; then press Symmetric. The two selected points will be equidistant from the origin.
5.7. Select two adjacent sides of the rectangle (connected at one corner), and press Equal length. Notice that due to the symmetry of the corner points, all sides are now of the same size.