Describe fully the single transformation that maps triangle A onto triangle B

Reflection over the x-axis

Step-by-step explanation:

To get from Triangle A to Triangle B, Triangle A must be reflected over the x-axis. On Triangle A, the left-most point is at (1, -2). The corresponding point on Triangle B is at (1, 2). The rule for reflecting over the x-axis is (x, y) -> (x, -y). So, (1, -2) -> (1, 2).

I hope this helps :))

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.