Question

Finding the Line of Reflection
On a coordinate plane, triangle A B C has points (negative 1, negative 1), (negative 2, negative 1) and (negative 2, negative 4). Triangle A prime B prime C prime has points (1, negative 1), (2, negative 1), and (2, negative 4).

What is the name of the line of reflection that maps the pre-image to the image?


y = x
y-axis
x-axis
x = 1

Answer 1

y-axis

Each point's x-coordinate is negated while the y-coordinate stays the same (e.g. (-1,-1) → (1,-1)), which is a reflection across the y-axis (x = 0).