I am using 5.520.6147.0 #9d8cd91e on a Windows PC.
I have an arc that needs to be extended to meet another line. I do not see a way to maintain the diameter of the arc while extending the arc manually by dragging the endpoint. When I click on the arc, the purple guideline that appears has the same radius as the arc I am trying to extend, but as soon as I click on the point to move it, the purple guideline changes to align with the X-Y plane and when I drag the point the diameter of the arc changes.