Rectangles and lines in a paginated report (Report Builder)
Applies to: 
Microsoft Report Builder (SSRS)
Power BI Report Builder
Report Designer in SQL Server Data Tools
Rectangles and lines can create visual effects within a paginated report. You can set display properties on these report items from the Border section of the Home tab, and set other properties in the Properties pane. You can add features like a background color or image, a tooltip, or a bookmark to a rectangle.
Rectangles and Lines as Report Parts
You can publish rectangles with the items that they contain separately from the report as report parts. Report parts are self-contained report items that are stored on the report server and can be included in other reports.
You cannot publish the report items within a rectangle as report parts. When people add the rectangle to a report, they get the rectangle and the items it contains. Read more about Report Parts.
Note
Report parts are deprecated for all releases of SQL Server Reporting Services starting with SQL Server Reporting Services 2019 and all releases of Power BI Report Server starting with Power BI Report Server September 2022.
Using a Rectangle as a Container
You can use a rectangle as a container for other items. When you move the rectangle, the items that are contained within the rectangle move along with it. An item within the rectangle shows the name of the rectangle in its Parent property. For more information about using a rectangle as a container, see Add a Rectangle or Container (Report Builder and SSRS) and Display the Same Data on a Matrix and a Chart (Report Builder).
Note
A rectangle is only a container for items that you either create in the rectangle or drag into the rectangle. If you draw a rectangle around an item that already exists on the design surface, the rectangle will not act as its container. The rectangle will not be listed in the item's Parent property.
When using rectangles to contain report items, consider how the items will be affected as a whole during report rendering. Report items that contain repeated rows of data (for example, tables) will expand to accommodate the data that is returned by a query, and this affects the positioning of other items in the rectangle. A table will push items down if they are positioned below the data region. To anchor an item in place, you can place the report item inside of a rectangle that has an upper edge above the lower edge of the table. For more information, see Rendering Behaviors (Report Builder and SSRS).
Adding a Report Border
You can add a border to a report by adding borders to the headers, footers, and report body themselves, without adding lines or rectangles. For more information, see Add a Border to a Report (Report Builder and SSRS).
How-To Topics
Add a Border to a Report (Report Builder and SSRS)
Add a Rectangle or Container (Report Builder and SSRS)
Add and Modify a Line (Report Builder and SSRS)