Triangle PQR is transformed to triangle P'Q'R'. Triangle PQR has vertices P(3, −6), Q(0, 9), and R(−3, 0). Triangle P'Q'R' has vertices P'(1, −2), Q'(0, 3), and R'(−1, 0).

Plot triangles PQR and P'Q'R' on your own coordinate grid.

Part A: What is the scale factor of the dilation that transforms triangle PQR to triangle P'Q'R'? Explain your answer.

Part B: Write the coordinates of triangle P"Q"R" obtained after P'Q'R' is reflected about the y-axis.

Part C: Are the two triangles PQR and P''Q''R'' congruent? Explain your answer.

1 answer

A: 1/3
reflection across y takes (x,y)→(-x,y)
dilation destroyed the congruency