a layout viewport is a window that displays a view of model space on a layout tab. You can create multiple layout viewports to display different views of your model at different scales.
To create the viewports in a layout tab, you can use three methods:
* From the Viewports dialog box: select a viewport configuration
* Create individual viewports by using the MVIEW command
* From the View Manager dialog box, generate named views and add them as layout viewpoints These methods will allow you to create and arrange viewports on your layout tab.
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD

Open the Sheet Set Manager: Type SHEETSET in the command line and press Enter.
Modify Page Setup: Right-click on the sheet set or individual sheets and select Properties.
Set Page Setup: Change the page setup to 12x18 PDF.
Publish: Click Publish to generate the PDF with the desired settings.
References:
* AutoCAD Help Documentation on Publishing Drawing Sheets

From the Delta option of the Lengthen command, enter 50 units and then select the right end of the line. This way, you can increase the length of the line by 50 units from its current endpoint without changing its direction or position2
https://www.learnvern.com/autocad-tutorial-in-hindi/how-to-use-lengthen-command

When creating a path array in AutoCAD, the objects being arrayed typically align with the direction of the path by default. To maintain the original orientation of the objects while following the curved path, you should turn off the "Align items" option.
* Select the Object: Choose the object you want to array along the path.
* Path Array Command: Use the ARRAYPATH command or go to the Array command and choose Path Array.
* Select Path: Select the path (curved line or arc) along which the objects will be arrayed.
* Turn Off Align Items: In the Array options, turn off the "Align items" checkbox to ensure that the objects maintain their original orientation.
This will keep the orientation of each object the same as the original, regardless of the curvature of the path.

* Setting Up Polar Tracking:
* Polar Tracking helps in creating lines at specific angles by snapping to predefined angle increments.
* Required Angles in the Exhibit:
* The exhibit shows angles of 45°, 60°, and 27°.
* Increment Angle: Set to 60° to cover the major angle increments.
* Additional Angle: Add 27° to cover the specific requirement in the drawing.
* Steps to Set Drafting Settings:
* Open the Drafting Settings dialog.
* Go to the Polar Tracking tab.
* Set the Increment Angle to 60°.
* Add 27° to the Additional Angles list.
* Conclusion:
* To draw the exhibit using Polar Tracking, set the Increment angle to 60° and add 27° as an additional angle.
References:
* AutoCAD User Guide on Polar Tracking.
* AutoCAD Help Documentation on Setting Increment and Additional Angles.