The coordinates of a quadrilateral are (1, 2), (4, 2), (1, 4), and (4, 4). after a transformation, the new coordinates are (1, −2), (4, −2), (1, −4), and (4, −4). which transformation occurred? a) (x, y)→(x + 2, y + 2) b) dilation; (x + 2), (y + 2) c) reflection across the y-axis d) reflection across the x-axis

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?