CAD tip # 14088:

There are several ways to create "better" behaving rectangles in AutoCAD. Here are three of them. First, a video demonstration:

1. Parametric constraints (purple rectangle) - if you use the AUTOCONSTRAIN command after creating a standard rectangle or square, constraints will be added to the geometry to ensure that the sides of the rectangle remain perpendicular and parallel when editing the corner of the rectangle at the grip. This is the simplest and most common way of creating true rectangles. For more information, see the tip 6832.
2. MView in model space (yellow rectangle) - a bit surprising solution for creating rectangles, copying the special entity "model view" intended for the paper space. Does not require geometric constraints. Just create a MView in paperspace and copy/paste it to the modelspace. See the CZ tip 13754.
3. Dynamic block (green rectangle) - you can use parametric dynamic blocks to create different kinds of constraints and rules for drawing and editing rectangles. For example, a rectangle growing symmetrically from its center, a rectangle preserving a given area, a rectangle with conditional geometric features based on its size, etc. See the video and see examples of dynamic DWG blocks in the Block Library for download - RectangleC, AreaBlock-1, DBlookup