Show that the line joining the origin to the point `(2,1,1)` is perpendicular to the line determined by the points `(3,5,-1)` and `(4,3,-1)dot`

Show that the line joining the origin to the point quad (2,1,1) is perpendicular to the line determined by the points (4,3,-1)

Show that the line joining the points (4,-3) and (0,7) is perpendicular to the line joining the points (5,2) and (0,0) .

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 through the points (1,-1,2) and (3,4-2) is perpendicular to the line through the points (0,3,2) and (3,5,6).

Show that the line through the points (-2,6) and (1,7) is perpendicular to the line through the points (3,-3) and (5,-9).

Show that the line thorugh the points (1,-1,2) and (3,4,-2) is perpendicular to the line through the points (0,3,2)andf (3,5,6).

Show that the line joining the points (2,-6) and (-4,-8) is perpendicular to the line joining the points (4,-2) and (6,-8) .

Line joining the points (3,-4) and (-2,6) is perpendicular to the line joining the points (-3,6) and (9,-18).

Show that the straight line joining the points (-1,0,-2) and (1,3,-1) is perpendicular to the straight line joining the points (9,1,-6) and (7,2,-5)