Question

Which of these describes the transformation of triangle ABC shown below?A) reflection across the x-axisB) reflection across the y-axisC) reflection across the line y=xD) translation

Answer 1

From the figure, we have the coordinates of the vertices:

ABC ==> A(2, 1), B(5, 1), C(1, 5)

A'B'C' ==> A'(-2, 1), B'(-5, 1), C(-1, 5)

Let's determine the type of transformation that occured here.

Apply the rules of rotation.

For a rotation acorss the y-axis, only the x-coordinates of the points will change to the opposite. i.e from negative to positive or from positive to negative.

For a rotation across the y-axis, we have:

(x, y) ==> (-x, y)

From the given graph, we can see that the only the x-coordinates changed from positive to negative.

Therefore, the transformation that occured here is the reflection across the y-axis.

ANSWER:

B) Reflection across the y-axis.