New Extrude

We'll now build the lower area of the part.

1. On the XY plane create the following sketch.

2. Click Add Geometry and pick the arc. Select Add Reference and pick the point shown in the area marked with a red circle.
   
   

3. Sketch the following sketch and set the dimensions as shown in the image below:
   

4. From the Solid menu, select New > Extrude and apply a delta of 350.
   

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