ArcGIS Pro 2.4 API Reference Guide
GetWidth Method (Element)
Example 

ArcGIS.Desktop.Layouts Namespace > Element Class : GetWidth Method
Gets the width of the element. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
Public Function GetWidth() As Double
public double GetWidth()

Return Value

Returns a Double
Exceptions
ExceptionDescription
This method must be called within the lambda passed to QueuedTask.Run.
Example
//Modify an element's width.

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  double elmWidth = element.GetWidth();
  elmWidth = 8.5;

  element.SetWidth(elmWidth); //You don't have to get to set; a shortcut would be: element.SetWidth(8.5);
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

Element Class
Element Members