What scale factor was used in going from the grey triangle to the yellow triangle?

The scale factor used was 2

Step-by-step explanation:

see the attached figure with letters to better understand the problem

we know that

A dilation is a non-rigid transformation that produce similar figures

If two figures are similar then the ratio of its corresponding sides is proportional and this ratio is called the scale factor

In this problem the dilation going from the grey triangle to the yellow triangle is an enlargement and its equal to the quotient length side AC by length side DE (corresponding sides)

we have

--->absolute value of the difference of the x-coordinates

--->absolute value of the difference of the x-coordinates

therefore

The scale factor used was 2

i am really confused im sorry