I dont know where zoos get these exhibit size figures from sometimes, I measured the main exhibit appears to be less than 800 square meters, and what appears to be a secondary yard behind this one is a little over 1100.
I don’t know it either. They have just one outdoor yard, sorry if my description was too short or not clear. I would say that it is around the size what you measured. Although it is not huge, I think that this is a quiet nice enclosure, my only complaint would be that the apes can’t get away from the public.