There are a number of ways you can control the layout of your RadTabControl control.
If you need to group your tab items in different rows, separating them by some specific criteria, just use the Boolean property IsBreak. This property belongs to the RadTabItem class and once set, all tab items that are after this one will be placed on a new row. Read more
You can control the orientation of the tab items by using the property TabOrientation. You can choose one of these options: to display them horizontally (Orientation.Horizontal) or vertically (Orientation.Vertical). Read more
The default placement of the tab control items is on top, but sometimes this is not what we need. Here is when the TabStripPlacement property comes. It allows you to define the exact position, the tab items should appear using the Telerik.Windows.Controls.Dock enumeration. The four possible choices are: - Dock.Bottom, Dock.Left, Dock.Right, Dock.Top.Read more
Control the heights of your tab item headers using the Boolean property AllTabsEqualHeight. If you set this property to True, all of your tab items will be automatically resized to the same header hight, except for those, which height has not been explicitly defined. Note that the header area of the tab control will be as high as the highest header element.
Control the vertical and horizontal alignments using the four properties HorizontalAlignment, HorizontalContentAlignment, VerticalContentAlignment and VerticalAlignment inherited from the base FrameworkElement class.