Open a sketch on the large model face.
Select the bottom line in the layout sketch, and
click Convert Entities 
on the Sketch toolbar.
In the dialog box, click closed contour, then click OK.
Now you can reference the layout for cuts sketch to create the first set of cuts. Because each cut should be slightly wider than the corresponding tab on the other half of the hinge, you use offsets from the layout sketch entities.
Open a sketch on the large model face.
Select the bottom line in the layout sketch, and
click Convert Entities on the Sketch toolbar.
In the dialog box, click closed contour, then click OK.
This copies the entire outside contour into the current sketch.
Select one of the vertical lines near the edge
of the part, then click Offset Entities
on the Sketch toolbar.
In the PropertyManager:
Set Offset
Distance 
to 1.
Select Reverse, if necessary, to offset the line towards the middle of the part.
Clear Select chain.
Click
OK 
.
Repeat steps 4 to 6 for the vertical line near the opposite edge of the part.
