As an example, this matrix shows a set of permutations for up to four intersections at four different points of entry. Obviously, this should only be taken as an indication of an almost unlimited range of possibilities. The chart structure: The vertical columns shows the four possible ways in which one or more streets may intersect with the square. The horizontal rows show the number of the streets intersecting with a square. centrally and at right angles to one side. off-centre and at right angles to one side. meeting a corner at right angles. oblique, at any angle and at any point of entry. Intersections of Street and Square: An Indicative Matrix A simple way to classify spatial types of squares can start by examining the number of street intersections.