Answer
Option B is correct.
E'F' is equal in length to EF.
Step-by-step explanation
When a figure is rotated through any degree clockwise or counterclockwise, the length of the figure stays the same.
This proves option B right and it proves options C and D wrong.
But to prove option A wrong, we need to find the coordinates of E'F'.
When a rotation of 270° counterclockwise about the origin is done on some coordinate, A (x, y), it transforms this coordinates into A' (y, -x). That is, we switch y and x, then add negative sign to x.
To obtain the coordinates of E' and F', we need to obtain the coordinates of E and F first.
E (1, -4)
F (5, -4)
When they are transformed through rotation of 270° counterclockwise about the origin, the change is that
A (x, y) = A' (y, -x)
E (1, -4) = E' (-4, -1)
F (5, -4) = F' (-4, -5)
E' (-4, -1) and F' (-4, -5) when marked out and drawn on this graph gives a vertical line that lies on x = -4 and covers from y = -1 to y = -5.
This indicates that E'F' is vertical and not horizontal like EF and thus, E'F' is not parallel to EF, rather, E'F' is perpendicular to EF.
Hope this Helps!!!