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##### ​Triangle PQR is transformed to triangle P'Q'R'. Triangle PQR has vertices P(8,

 Algebra Tutor: None Selected Time limit: 0 Hours

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. 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.
Feb 10th, 2015

Scale factor for dilation is 1/2 or 0.5

because 1/2 (8,0) = (4,0) ; 1/2(6,2) =(3,1) ; 1/2(-2,-4) = (-1,-2)

If P'Q'R' is reflected in y axis x coordinate will be same but y coordinate will be negatived

P" ( 4,0)

Q" (3,-1)

R"(-1,2)

Feb 10th, 2015

So, the figures are congruent then right?

Feb 10th, 2015

Yes . They are congruent

Feb 10th, 2015

But I don't understand though, can you explain why they're congruent in short-term?? I just want to make sure im getting this right.

Feb 10th, 2015

The triangle is reflected. the sides are equal. Areas are equal.

Feb 10th, 2015

Distance between (4,0) and (3,-1) = sqrt[(4-3)^2+(0-(-1))^2] = sqrt[1+1] =sqrt (2)

In the other triangle distance between (4,0) and (3,1) =sqrt[(4-3)^2+(0-1)^2] =sqrt(1+1) =sqrt(2)

and so on.

Feb 10th, 2015

I need some examples or a formula to help me because i'm not understanding, a lot of numbers and symbols and extra pronunciations don't help. I'm not satisfied, I think we can get more simple in explaining here... I need like some 8th grade website that may help because i think i'm getting no where.

Feb 10th, 2015

I am sorry.The reflections on the y axis must be  (-4,0), (-3,1), and (1,-2)

I want to upload a ppt file but it does not get uploaded here. Can you give me your email?

Feb 10th, 2015

Now I am successful. Look at the slide 1 and slide 2

Slide 2 is the reflection of slide 1 on the y axis.

Through the figure, you can visualize that they are congruent.

Feb 10th, 2015

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Feb 10th, 2015
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Feb 10th, 2015
Dec 6th, 2016
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