To create a dome:
Click Dome on the Features toolbar, or click Insert > Features > Dome.

You can create one or more dome features simultaneously on the same model.

Dome PropertyManager Options

Faces to Dome Select one or more planar or non-planar faces.
You can apply domes to faces whose centroid lies outside the face. This allows you to apply domes to irregularly shaped contours. Example: Applying a Dome to Irregular, Non-Planar Faces
  Distance Set a value for the distance by which the dome expands.
Reverse Direction Click to create a concave dome (default is convex).
Constraint Point or Sketch Control the dome feature by selecting a sketch that contains points to constrain the shape of the sketch. When you use a sketch containing points as a constraint, the Distance is disabled.
Direction Click Direction , and select a direction vector from the graphics area to extrude the dome in a direction other than normal to the face. As a direction vector, you can use a linear edge or the vector created by two sketch points.
  Elliptical dome Specify an elliptical dome for cylindrical or conical models. An elliptical dome's shape is a half ellipsoid, with a height equal to one of the ellipsoid radii. Example: Creating an Elliptical Dome
  Continuous dome Specify a continuous dome for polygonal models. A continuous dome's shape slopes upwards, evenly on all sides. If you clear Continuous dome, the shape rises normal to the edges of the polygon. Example: Creating a Continuous Dome
Continuous dome is not available for four-sided polygons or when you use a Constraint Point or Sketch or a Direction vector.
  Show preview Check for a preview.
On cylindrical and conical models, you can set Distance to 0. The software calculates the distance using the radius of the arc as a basis for the dome. It creates a dome that is tangent to the adjacent cylindrical or conical face. Example: Creating a Dome with Zero Distance