This question was not very popular among the candidates.  However, the few candidates who attempted it were able to describe the ranging poles and arrows correctly.  Some however could not properly indicate how they would overcome an uncompleted building which pose an obstacle to chaining.  The expected answers include:

-           select two points A and B on the chain line close to the uncompleted building;
-           erect two equal and parallel perpendicular lines each at points A and B to
            extend beyond the uncompleted building;
-           mark two ends C and D respectively;
-           produce CD beyond the uncompleted building;
-           mark two points E and F;
-           from points E and F drop two equal and parallel perpendicular lines to the points G and H;
            -           AC is equal and parallel to BD, GE and HF;
            -           G and H are in line with the chain line;
            -           measure DE and record the distance;
            -           chain line BG is equal and parallel to line DE;
            -           continue the measurement from G;
            -           diagram.