回複：買的房子麵積比售房廣告上的小

Thanks for all the replies.
Forgot to mention that the house is located in Ontario, Canada, and the laws and regulations here are probably quite different from those in the US. However, I think people's common sense as well as the principle of making a law to protect public's interests should be the same on both sides of the border, so to me any samilar cases, regardless whether it is in Canada or the US will be very helpful.
I have already contacted my lawer about this matter, and he suggests me get an independent appraiser to measure the dimensions in question to make sure such discrepancies do exist. He would send a letter to the seller's lawer if we have the evidence. Then we will see what would happen next.