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From the Sketching tab, use the Circle tool to draw a circle centered at the origin. Again, Make sure your cursor displays a P near the origin before you begin sketching. Next, use the Line tool to draw two lines along the X and Z axis. We only need to create a quarter of the full sketch to create the 1/8 model. Select the Trim tool and click on any sketch outside the quarter circle enclosed by the lines and the full circle. Use the Radius dimtension tool to set the radius of the quarter circle to 4 mm.
The size of the specimen compared to the shell:
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