Hi Paul, probably something like:

Create a cylinder:



Go to the top view and draw in your wedge shape:



Extrude it:



Select the extruded plug and do Transform > Array > Circular to replicate it:



Select the cylinder and do Construct > Boolean > Difference and pick the plugs as the cutting objects:



Now you can just select the whole object:



And run Fillet to round off the corners:



For filleting you can select an entire object as the input to fillet which fillets all sharp edges of that object. If you need to target specific edges you can pick just some edges - in a case like this select just 1 edge to go into edge sub-object mode and then go to a side view and do a window select to grab a whole bunch more by capturing them within one drag window selection.

Hope this helps!

- Michael