Answer:
rotation 180° about (1, 4)
Step-by-step explanation:
When rotation is made about origin, i. e., point (0, 0); points of the shape transform from (x, y) to (-x, -y). But when the rotation is about point (x0, y0) the points transform from (x, y) to (-x +2*x0, -y +2*y0); notice that rotation about origin is a special case of this more general rule.
Then, the transformations about point (1, 4) are:
G (5, 4)-> (-5 + 2*1, -4 + 2*4) -> F (-3, 4)
I (5, 0)-> (-5 + 2*1, -0 + 2*4) -> E (-3, 8)
J (8, 0)-> (-8 + 2*1, -0 + 2*4 ) -> D (-6, 8)