Description
When an arc drawn with the Radius tool is zoomed in on, it disappears as soon as all of its anchor points fall outside the viewport. The arc should still render as long as any part of its geometry intersects the visible area.
This is noticeable when using the Radius tool to draw a full circle, which is done by placing the anchors anti-clockwise along the arc instead of clockwise. In that case the anchors sit on a small portion of a large circle, so zooming in on any other part of the circle pushes all anchors off-screen and the whole shape vanishes.
Screenshots
Before zooming in :
After zooming in :

Description
When an arc drawn with the Radius tool is zoomed in on, it disappears as soon as all of its anchor points fall outside the viewport. The arc should still render as long as any part of its geometry intersects the visible area.
This is noticeable when using the Radius tool to draw a full circle, which is done by placing the anchors anti-clockwise along the arc instead of clockwise. In that case the anchors sit on a small portion of a large circle, so zooming in on any other part of the circle pushes all anchors off-screen and the whole shape vanishes.
Screenshots
Before zooming in :
After zooming in :