To create a hexahedron bounded by bilinear faces, in the Geometry toolbar, click 
More Primitives>Hexahedron (

). You can also right-click the 
Geometry node to add this node from the context menu. Then enter the properties of the hexahedron using the following sections:
 
    From the Type list, select 
Solid or 
Surface to specify if the hexahedron is a solid object or a (hollow) surface object.
 
    The coordinate system in which the coordinates of the vertices above are interpreted. From the Work plane list, select 
xy-plane (the default, for a standard global Cartesian coordinate system) or select any work plane defined above this node in the geometry sequence. If you choose a work plane, the work plane and its coordinate system appear in the Graphics window, using an extra coordinate triad with the directions 
xw, 
yw, and 
zw (which are then used to specify the hexahedron’s position).
 
    Select the Resulting objects selection check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the hexahedron consists of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option from the 
Show in physics (
Show in instances if in a geometry part) list: 
All levels, 
Domain selection, 
Boundary selection, 
Edge selection, or 
Point selection. The default is 
Domain selection, which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose 
Boundary selection. These selections do not appear as separate selection nodes in the model tree. Select 
Off to not make any selection available outside of the geometry sequence. From the 
Color list, choose a color for highlighting the resulting objects selection. See 
Selection Colors.
 
    
    Select the Construction geometry check box to make the resulting objects available only in the feature’s geometry sequence. For more information see 
Construction Geometry.