Question

Can someone help me? https://media.glynlyon.com/g_geo_2012/12/img_geou12a_49.gif

The question is "what is BD?" I think AD is 5, but that's as far as I got.

Answer 1

My choices are
7.5
6.5
6
5

Answer 2

Oh I also just noticed that AC and CE have a ratio of 4/5, so if I did that with BD, would I get 5?

Answer 3

well we know that ACE and ABD are similar triangles

so that means the similar sides must be proportional


so the ratio of AC to AB must equal the ratio of CE to BD

if AC = 12, AB = 4

then the ratio is 12:4 ---> 3:1

CE = 15

so what value for BD would make 15:BD the same as 3:1 ?

Answer 4

@Phasmatis that approach would work too! yes, BD is 5

Answer 5

Alright, thank you very much!

Answer 6

you're welcome