Question

Triangle J'K'L' shown on the grid below is a dilation of triangle JKL using the origin as the center of dilation: http://prnt.sc/d5rm2g

Which scale factor was used to create triangle J'K'L'?
4
1 by 4
2
1 by 2

Answer 1

Scale of dilation is obtained by the ratio
k=image size (after transformation/preimage size (before transformation)
For example, if AC measures 5 units, and A'C' measures 15 units, then the dilation factor k equals
k=mA'C'/mAC=15/5=3
when k>1, the image is magnified,
when k<1, the image is smaller.

Answer 2

you mean JKL and J'K'L? right/

Answer 3

@mathmate

Answer 4

Yes, I'd like you to apply to JKL and J'K'L'.
What I was describing was just an example which mapped from ABC to A'B'C'.
The idea would apply to any other transformation PQRS to P'Q'R'S'.
\(If\) you know the centre of dilation (as in this case) is situated at origin, you can also take the ratio OA'/OA as the scalef factor.