#Slot

Key O. Two centres and a width give an elongated hole with round ends.

Click the first centre, the second centre, then set the width (it can also be typed in the top bar).

#What you get

Two parallel lines and two arcs held by tangencies and equal radii. Such a slot stays a slot through any change: drag a centre and the arcs follow without coming apart.

#Why use the tool

The same shape can be assembled from two lines and two arcs by hand, but then the tangencies are yours to place, and any of them can quietly fall off. The tool places all of them at once.