Fix of a plane table from three known pointsThe accuracy with which a plane table station can be located through three-point problem is known as its fix. The fix is good when instrument station T is within the triangle, and particularly when it is at the orthocentre and the middle station is much nearer than the other. On the other hand, the fix is bad or poor when the instrument station T is near the circumference of the circumscribing circle. So, the accuracy of the fix depends on the relative positions of the plotted points and that of the location of the plane table station. Thus the choice of plotted objects and location of the table should be made to get a strong fix.