Question

Triangle PQR is transformed to triangle P′Q′R′. Triangle PQR has vertices P(8, 0), Q(6, 2), and R(−2, −4). Triangle P′Q′R′ has vertices P′(4, 0), Q′(3, 1), and R′(−1, −2).

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. (4 points)

Part B: Write the coordinates of triangle P′′Q′′R′′ obtained after P′Q′R′ is reflected about the y-axis. (4 points)

Part C: Are the two triangles PQR and P′'Q′'R′' congruent? Explain your answer. (2 points)

Answer 1

Ok, after you plotted the two triangles, did you not notice that ...

PartA: somebody simply took half of the coordinates of the first
triangle to get the 2nd triangle ?
So what is the scale factor?

PartB: if any point is reflected in the y-axis, its y value stays the same, but
but its x value becomes the opposite.
so Q'(3,1) ----> Q''(-3,1) etc

PartC: to be congruent, the two triangles must have all corresponding sides and angles equal to each other. Is that the case?
Do they even have the same area??