△ABC is rotated 180 degrees about the origin to become △A'B'C'. Then △A'B'C' is translated 3 units down to become △A"B"C". Because the transformations are both rigid, the pre-image and image are congruent.
In Euclidean Geometry, the mapping rule for the rotation of a geometric figure about the origin by 180° in a clockwise or counterclockwise direction can be modeled by the following mathematical expression:
(x, y) → (-x, -y)
Point A (1, -1) → Point A' (-1, 1)
Point B (4, -2) → Point B' (-4, 2)
Point C (7, 2) → Point C' (-7, -2)
Next, we would apply a translation 3 units down to the new figure (△A'B'C'), in order to determine the coordinates of its image as follows;
(x, y) → (x, y - 3)
A' (-1, 1) → (-1, 1 - 3) = A" (-1, -2).
B' (-4, 2) → (-4, 2 - 3) = B" (-4, -1).
C' (-7, -2) → (-7, -2 - 3) = C" (-7, -5).
Therefore, the resulting figure must be located in the third quadrant as illustrated in the diagram shown above.