You haven't provided the coordinates of the original trapezium, therefore, I can only help with the concept.
From the givens, we can know that the rotation was 90° counter-clockwise about the origin.
<u>The rule for this rotation is:</u>
(x , y) ..............> (-y , x)
This means that to get the points of the rotated image, negate the y-value then exchange it with the x-value
<u>Examples:</u>
(1 , 3) rotated 90° counter-clockwise about the origin will give (-3 , 1)
(-2 , 4) rotated 90° counter-clockwise about the origin will give (-4 , -2)
(1 , -2) rotated 90° counter-clockwise about the origin will give (2 , 1)
(-3 , -5) rotated 90° counter-clockwise about the origin will give (5 , -3)
Hope this helps :)
