You can copy any element, dimension, or object by selecting it and clicking Copy on the Main toolbar. Copy places the selected item on the Clipboard. When you click Paste on the Main toolbar, the item is placed on the drawing sheet.
You can also copy an element with the Select Tool. You click the Select Tool on the Draw toolbar, select the element, and press CTRL as you drag the element across the drawing sheet. You can also copy several selected elements in the same manner.
When you copy elements that have relationships, the relationships are copied and retained when possible. For example, if you make a copy of two related lines, the relationship is also copied. However, if you copy one of two lines that are related to each other, the relationship is not copied.