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1. Select the center point of the sphere. The point will be projected onto the current workplane.
   
2. Click to size the sphere, or enter the radius in the Inspector Bar.
   
   The sphere is created, centered on the workplane.
   

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Sphere Properties

The Properties window of a sphere (and hemisphere) contains a Sphere page, in which you can set the radius.

For TC Surface Options, see TC Surface Properties.