The original triangle has the coordinates $(1, 3)$, $(3, 2)$, and $(4, 2)$, and the transformed triangle has the coordinates $(-1, 3)$, $(-3, 2)$, and $(-4, 2)$.

To find the rule that describes the transformation, we can observe the change in the coordinates:

• The $x$-coordinates of the points have been negated, while the $y$-coordinates remain unchanged.

This type of transformation corresponds to a reflection over the $y$-axis, where every point $(x, y)$ is transformed to $(-x, y)$.

Therefore, the rule that describes this transformation is:

Reflection over the $y$-axis.

Would you like more details or further clarification?

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Here are some related questions to expand your understanding:

1. How would the transformation change if the triangle were reflected over the $x$-axis instead?
2. What would happen to the coordinates if the triangle were translated 3 units downwards?
3. How do you determine the rule of transformation for a rotation of 90 degrees around the origin?
4. If the triangle was dilated by a scale factor of 2, what would the new coordinates be?
5. How do you represent transformations using matrix multiplication?

Tip: In reflections, the axis over which the reflection occurs determines whether the $x$- or $y$-coordinates change signs.