You have a triangle with the following vertices:
F (6,3)
G(3,4)
H(1,7)
If the triangle is rotated by 180° around the origin of the coordinate system, the new coordinates of the given vertices will be:
F (6,3) -> F'(-6,-3)
G(3,4) -> G'(-3,-4)
H(1,7) -> H'(-1,-7)
That is, the ne vertices has the same coefficients, but with opposite sings.
Then, the answer is:
F(-6, -3), G'(-3,-4), H'(-1, -7)