Undo Vertex
If at any time you make a mistake while entering geometry, you may "undo" the vertices of the boundary you are entering, with the vertex Undo option, as follows:
- Select Undo
from the right-click menu, OR - Type u followed by Enter in the prompt line.
Either action will remove the last vertex from the current polyline you are entering. Undo can be repeated any number of times to remove successive vertices from a boundary you are drawing – experiment with this option to see how it works.