False / Dropped Ceiling for LED Strip

[ambient]

I’m planning to drop a portion of a ceiling to incorporate an uplighting LED strip - aiming to create a look similar to the attached images (just to clarify, these aren’t my photos).

Does anyone have any insight into the appropriate dimensions for this type of design? Without guidance, I’d have to estimate based on the photos, but I’m concerned that might lead to inaccuracies and compromise the final result.

Furthermore, does anyone know the correct term for this style of ceiling? I’ve searched extensively online but haven’t found anything commonly used. Knowing this could help me gather further information.