The compass should be used whenever possible as it is more accurate than pacing. Although a relatively primitive instrument, with practise the compass can measure bearings to within a degree. As errors increase with the distance to the object being sighted, do not take bearings on objects exceeding 150 m.
a: The measurement of point from three directions, the resultant sight lines produce a coincident point. This is not common in the field.
b: The more likely situation. The point is marked as on the horizontal sight line between the two intersecting vertical sight lines.
c: The resultant triangle is too large to fix the point. Try again.