In the movie Flatland A. Square visits Spaceland and from there observes many different lands Solution \'A. Square\' is referred to as a square. We know that square is a two dimensional figure. We also know that square is made up of infinitely many points. Since a point has zero dimensions and it doesn\'t occupy any real space. That is the reason why it cannot see the square. On the other hand, square is two dimensional, and it occupies infinitely many points, so it can see all those points. Since square can also be considered to contain infinitely many lines (which are one dimensional), so it can easily see all the line it contains. However, line can only see that part of the square which it occupies. So it can see the portion lying in one dimension only. The other portion that lies on the other dimension cannot be seen by the line. Since \'square\' as well as \'flat\' are two dimensional figures, so that can see each other quite well as they occupy each other. A tesseract is a four dimensional version of a square. For example square it two dimensional, cube is three dimensional and tesseract is 4 dimensional. Now if a tesseract meets a square in the spaceland, tesseract will be able to see all about square because tesseract occupies it completely. However, square won\'t be able to see the tesseract entirely. Square will only be able to see the part of the tesseract that lies on it, i.e. two dimensional part. Rest of the part of tesseract will not be accessible to the square. Hope it makes sense..