Provide a spinner for changing the values (distance, angle, diameter) and show its effect on the geometry "live".

[raindropsfromsky]

Currently, we enter the value and press Enter to let the new value take effect.
This does not allow us to eyeball the effect and adjust the value accordingly.
So we have to repeat the whole exercise repeatedly to fine-tune the effect.

Instead, provide Blender's spinner control, where we can not only enter a new value, but also-
(a) click on the < and > buttons, or
(b) click inside the spinner and drag left/right to change the value

As the value changes, Sketcher should show its effect on the geometry "live".