What tool would you primarily use for basic shapes in After Effects?

The Rectangle Tool is specifically designed for creating basic geometric shapes such as rectangles and squares in After Effects. It allows users to quickly and easily create these shapes by clicking and dragging in the composition panel. This tool is ideal for tasks that require straightforward geometric designs, making it a fundamental asset for animation and compositing in After Effects.

While the Pen Tool is powerful for creating custom shapes and paths, it is more complex and often used for detailed and intricate designs rather than basic shapes. The Shape Tool could be interpreted as a broader term that includes tools for creating shapes, but in the context of the specific tools presented in the choices, the Rectangle Tool is the most appropriate. The Brush Tool is primarily used for painting and texture work, thus it does not serve the purpose of creating basic geometric shapes directly.