KB: Edit board shape

Solution Details

Try these steps:
1. from top menu, View ► Board Planning Mode (or simply hit '1' for the keyboard shortcut)
2. from top menu, Design ► Edit Board Shape (or simply hit 'd' twice for the keyboard shortcut)
(see note below)
3. left-click and drag white edit handles, which appear as you hover over a board edge


 
Here's a link to the relevant section of documentation on Board Shape for editing the board shape:
https://www.altium.com/documentation/altium-designer/pcb-obj-boardshapeboard-shape-ad#!edit-board-shape

Here's additional information that may be helpful:
Changing Board Sizes in Altium Designer:
https://resources.altium.com/p/layout-guide-changing-board-sizes-altium-designer
Circuit Board Sizes and Shapes, How to Make a PCB:
https://resources.altium.com/p/circuit-board-sizes-and-shapes-how-make-pcb
Defining the PCB Shape:
https://www.youtube.com/watch?v=vqHlxtV8lwE&t
Defining the Board Shape:
https://www.altium.com/documentation/altium-designer/defining-the-board-shape-ad#interactively-defining-and-editing-the-board-shape

Note:  For AD21 and newer, If you don't see the Edit Board Shape under the Design menu, you many need to enable Legacy.PCB.RighidFlex  Preferences ► System ► General ► Advanced... button, search for "flex", then check the box in the Value column for Legacy.PCB.RighidFlex, close and restart Altium.