Question

I’m confused on whether its 12 or 18, pls help

Answer 1

12 ft I think because 18 would be too long

Answer 2

Answer:

Notice that the triangles ABC and AMN are similar.

Thus:

$\frac{AC}{MN} = \frac{AB}{MB}\\\\\frac{AC}{6} = \frac{8}{4} = 2\\\\ AC = 12\,\,ft.$