Show that the line segment joining the points A(1, 2, 3) and B(4, 5, 7) is parallel to the line segment joining the points C(-4 ,3, -6) and D(2, 9, 2).

If the line segment joining the points A(7, p, 2) and B(q, -2, 5) be parallel to the line segment joining the points C(2, -3, 5) and D(-6, -15, 11), find the value of p and q.

Show that the line joining the points A(2, 3, 1) and B(4, 6, 2) is perpendicular to the line joining the points C(6, -2, -9) and D(4, -1, -8).

Prove that the straight line joining the points A(4, -3, 2) and B(2, -1, -1) is parallel to the straight line joining the point C(7, -3, 5) and D(1, 3, -4).

Show that the mid-point of the line segment joining the points (5, 7) and (3, 9) is also the mid-point of the line segment joining the points (8, 6) and (0, 10).

Find the midpoint of the line segment joining the points (-3,4) and (1, - 2).

Show that the line joining the points A(4,8) and B(5,5) is parallel to the line joining the points C(2,4) and D(1,7).

Show that the line joining the points A(4,8) and B(5,5) is parallel to the line joining the points C(2,4) and D(1,7).

Show that the mid-point of the line segment joining the points (5,\7) and (3,\9) is also the mid-point of the line segment joining the points (8, 6) and (0, 10) .

Show that the line joining the point A(1,-1,2) and B(3, 4, -2) is perpendicular to the line joining the points C(0,3,2) and D(3,5,6).

Show that the line segment joining the points (5,7), (3,9) and (8,6), (0,10) bisect each other.