Convert to sketch

[n3wb1e]

Hi there,
I drew an extruded circle. On the top of the circle I cut away a rectangle using extruded cut. Now I have a face on the cut away part where I want to place 3 evenly spaced holes but Ive reached a dead end. Do I need to convert this face to a sketch? If so how do I achieve this? If not then what do I do from here?

Thank you.

 

[bvrooman]

start your sketch from a plane perpendicular to the axis, either from an existing planeor a new one constructed from the existing planes and temporary axisand cut outward from there through all. I take it to mean you need three holes 120deg apart? Then pattern the hole feature on the cylinders temporary axis.
first visualize then achieve.