Thanks for the replies.
I think it's somewhat old. I am not the original buyer. And it's a NeilPryde (or something like that).
The battens are not full length (3 in total), and it's not far off from a triangular shape.
I looked everywhere on it, and it does not say anything about the size.
The measurements I took are approximate with a measuring tape, but I mean, in worst case it's an error margin of 1/2 feet.
As for the other 4.5, you could clearly see it had a lot less surface. It was approximately the same luff length, just half the width.
I'll try to post a picture to give a general idea.