We notice that the upper trapezoid is symmetric to the lower one & the line of symmetry should be a horizontal line (mirror line) where any point of the upper vertices should be at equal distance (perpendicular) with the related vertices of the lower one from this horizontal line: Note that QQ" =4 units, Hence the line of symmetry is the perpendicular to QQ' at 2 units
We can take out one of the points such as H (2,6) and then take it's dilation H' (1,3)and see that 2 and 6 were both multiplied by 1/2 to get 1 and 3, so the scale factor is 1/2
