General Mathematics Paper 2, WASSCE (PC), 2016

Question 11

Using ruler and a pair of compasses only,
         

  1.  construct:
  1. parallelogram ABCD with diagonals |AC| = 10 cm and |BD|= 7 cm intersecting at K and ∠BKC = 60o;
  2. the locus, ll, of points equidistant from B and C;
  3. the locus, l2,of points 5 cm from B. 

 

  1. locate the points of intersection M and N of loci l1and l2.
  1.  Measure:

 

  1. |MN|;
  2. |BC|;

Observation

 

This question was reported to be quite unpopular among the candidates. The performance of those who attempted it was also reported to be poor. Candidates were expected draw the line BD to be 7 cm long and label its mid-point K. They would then construct angle 60o at K. Using K as the centre with radius 5 cm, candidates were expected to draw arcs above and below the line BD and thereafter produce the angle 60o to intercept the two arcs to obtain the line AC. Join the four points to obtain the parallelogram ABCD. The locus of points equidistant from B and C was the perpendicular bisector of the line joining points B and C. The locus of points 5 cm from B was a circle centre B and radius 5 cm. M and N were the points of intersection of the two loci and the length of the line joining M and N was measured with the ruler as 9 cm (± 0.1 cm). the length BC was measured as 4.4 cm (± 0.1 cm).