To reflect a triangle across the x-axis, the $y$-coordinate of each point is negated while the $x$-coordinate remains unchanged. This transformation is represented algebraically as:

$(x, y) \to (x, -y)$

Correct Answer:

B. (x, y) → (x, -y)

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Would you like further details or clarification on this transformation?

Related Questions:

1. How would the algebraic representation differ for a reflection across the y-axis?
2. What happens to the coordinates if the triangle is reflected across the line $y = x$?
3. How would you write the rule for translating the triangle 3 units up and 2 units left?
4. How can you verify that a reflection was performed correctly using coordinates?
5. What changes would occur to triangle $PQR$ if reflected across the line $y = -x$?

Tip:

For reflections, remember that the axis being reflected across determines which coordinate changes sign. The $x$-axis affects $y$, and the $y$-axis affects $x$.