Observation

This question invloves finding the true shape of a triangular lamina and stating its angle of inclination to the horizontal plane.

Many candidates attempted this question and their perfomance was fairly okay.

Candidates were expected to do the following:

TRIANGULAR LAMINA
A.        COPYING THE GIVEN VIEWS
(i)         draw the X-Y axis;
(ii)        draw the plan correctly;
(ii)        draw the front elevation.

B.        DRAWING THE FIRST AUXILIARY ELEVATION
(i)        draw the horizontal line from R1 to T1in the front elevation;
(ii)        project down from T1 to T in the Plan;
(iii)       join lines R to T and produce ;
(iv)       draw lines from Q and P parallel to line RT produced and extending the lines;
(v)        draw X1 –Y1 axis perpendicular to the parallel lines drawn from points P, Q and R ;
(vi)       locate points Q2, R2 and P2 as corresponding distances of Q1, R1and P1 from X – Y axis;
(vii)      draw lines Q2, R2 and P2  as the first auxiliary elevation edge view of the lamina.

C (I)    DRAWING THE SECOND AUXILLIARY ELEVATION ( TRUE SHAPE OF THE TRIANGULAR LAMINA)

(i)        draw X2 _ Y2  axis parallel to line Q2 P 2;
(ii)        draw perpendicular lines from points Q2,R2 and P2;
(iii)       locate  pointsQ3,R3 and P3  on X2 –Y2 axis as corresponding distances of points Q, R, and P from X1 –Y1 axis;
(iv)       join the points Q3,R3 and P3  to obtain the true shape of the triangular lamina.

C (II)   measure and state the angle of inclination to the horizontal plane HP as angle Q2 X1 Y1= 480 ±10.

D         measure and state the lengths of sides as P^3 Q^3 and R^3 P^3.