Triangleabc is transformed to form    trianglea'b'c' . a is at (2, 4) , b is at (3, 9) and c is at (4, 1) . which transformation of △abc results in △a'b'c' ? drag and drop the the correct answers into the each box to complete the sentence.

A=(2,4); B=(3,9); C=(4,1)
A'=(4,-2); B'=(9,-3); C'=(1,-4)

All the points P=(x,y) change to P'=(y,-x), this corresponds to a rotation counterclockwise about the origin, then:

Triangle ABC is
First box: rotated counterclockwise
Second box: 90° about the origin
to form triangle A'B'C'