Choose Sketching tab→Draw group→Project to Sketch.
If the Project to Sketch Options dialog box displays, set the options you want, then click OK.
Click a planar face or reference plane to lock sketch input to the plane onto which you want to project the elements.
Select one or more elements to project onto the sketch plane.
Tip:
When you use the Inter-Part Copy command to copy faces from other parts in the assembly into the active document, these faces become part of the active part, and you can use the Project to Sketch command to associatively copy their edges.
You cannot project an element that is perpendicular to the profile plane.
You can extend the ends of open projected elements.
You can control whether or not silhouette edges of parts are locatable with the Silhouette Edge Locate command.