Triangle ABC is transformed with the center of dilation at the origin. Pre-image: △ABC with vertices A(−3, 4), B(−1, 12), C(4, −2) Image: △A'B'C' with vertices A'(−0.6, 0.8), B'(−0.2, 2.4), C'(0.8, −0.4) What is the scale factor of the dilation that maps the pre-image to the image?

Triangle ABC is transformed with the center of dilation at the origin Preimage ABC with vertices A3 4 B1 12 C4 2 Image ABC with vertices A06 08 B02 24 C08 04 Wh class=

Respuesta :

When triangle ABC is transformed with the center of dilation at the origin. The image will  become △ABC with vertices A(−3, 4), B(−1, 12), C(4, −2). The scale factor of the dilation that maps the pre-image to the image is 8:3

Answer:

The scale factor of the dilation is 0.2 or [tex]\frac{1}{5}[/tex].

Step-by-step explanation:

The vertices of pre-image are A(−3, 4), B(−1, 12), C(4, −2).

The vertices of image are A'(−0.6, 0.8), B'(−0.2, 2.4), C'(0.8, −0.4).

If scale factor of dilation is k and center of dilation is origin, then

[tex]P(x,y)\rightarrow P'(kx,ky)[/tex]

It is given that A(−3, 4).

[tex]A(−3, 4)\rightarrow A'(k(-3),k(4))[/tex]

Therefore the image of A is

A'(k(-3),k(4))

A'(-3k,4k)             .... (1)

It is given that the image of A is

A'(−0.6, 0.8)       .... (2)

On comparing (1) and (2), we get

[tex]-3k=-0.6[/tex]

Divide both sides by -3.

[tex]k=\frac{-0.6}{-3}[/tex]

[tex]k=0.2[/tex]

If center of dilation is origin, then the direct formula to calculate scale factor is

[tex]k=\frac{\text{coordinate of x'}}{\text{coordinate of x}}[/tex]

[tex]k=\frac{-0.6}{-3}[/tex]

[tex]k=0.2[/tex]

Therefore the scale factor of the dilation is 0.2 or [tex]\frac{1}{5}[/tex].