Answer:
Ok, when we have a point (x, y) and we do a rotation of 90° the new points will actually depend on the quadrant where we are, but it will always change the order to (y, x) but this does not end here, because depending on the quadrant where the point ends, the signs will change as follows.
1st quad (+y, +x)
2nd quad (-y, +x)
3rd quad (-y, -x)
4th quad (+y, -x)
So if we are in the second quadrant, the transformed point will be in the first quadrant
Now, we have that the points G and H are:
G = (-1, 3)
This point is in the second quadrant, so it moves to the first quadrant (where bot values must be positive).
The new point will be:
G´ = (3, 1)
And the other point is:
H = (-4, 0)
It also rotates to the first quadrant, so the new point will be:
H' = (0, 4)
