Catriona's Pentagon

Topic:
Area
Another lovely Catriona Shearer puzzle with a disturbing degree of freedom. The original puzzle was just knowing the distance between A and B to be 6 (n here) what is the area of the pink pentagon? Original puzzle: https://twitter.com/Cshearer41/status/1264175488102289408?s=20 And then I wondered what if the 6 changes and it's a lovely pattern, too.
Image