You did not need to create a detail view (section line off part) to create a Projected view.
You can Retrieve Sketch(s) from ipt or
click on the viewport to highlight (red) the boundary.
Hit s on the keyboard to start a sketch within the view.
Project Geometry and select the edges you wish to use as reference.
Right Mouse Button and select Done (this is important - different than in ipt sketch environment).
Sketch in any additional reference geometry you need snapping to projected geometry (like bolt circle) or angled reference lines.
Click Finish Sketch to get out of sketch mode.
Dimension as desired.