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# similar shapes question watch

1. Attachment 726900

Hey there I'm stuck on this question, I tried to get help from the previous example to work out the scale factor, but DA is not given so how can I work it out? Thanks
3. (Original post by jamesgillian123)
...
You need to scale AB to get AD. Then BD = AD - AB
4. (Original post by RDKGames)
You need to scale AB to get AD. Then BD = AD - AB
so is it Scale factor 1.5 because its 12 to 18, so 20 x1.5 = 30, 30-20 = 10 that right?
5. (Original post by RDKGames)
You need to scale AB to get AD. Then BD = AD - AB
forgot ot add this is also my acc that was from my phone
6. (Original post by jamesgillian123)
First to find the scale factor you'd do the larger length 18/12 to find 1.5 then multiply that by 20 to find the length of the whole side DA which is 30 then minus 20 from it to find the length DB which is 10cm.

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