To Place a Rectangular Fence

Select the Place Fence tool ( Drawing > Home > Selection > Fence Tools split button).

If a fence already exists, it is removed.
In the tool settings window, set Fence Type to Block.
Define the opposite corners of the rectangular fence by:

Data points
1. Enter a data point to define one corner.
2. Enter a data point to define the diagonally opposite corner.
Place Fence, with Fence Type set to Block

Or click and drag
1. Enter a data point to define one corner.
2. Enter a data point to define the diagonally opposite corner.