Explanation:
this creates 2 similar triangles.
that means all angles are the same. and all the side lengths of one triangle correlate to the side lengths of the other triangle by the same multiplication factor.
2 × f = 5
f = 5/2 = 2.5
now the same factor applies to the relation of the heights :
5'4" × 5/2
to help us, let's convert her height into a fraction too.
1 ft = 12 in
4 in = 1/3 ft
5'4" = 5 1/3 ft = 16/3 ft
16/3 × 5/2 = 80/6 = 40/3 = 13 1/3 ft = 13'4"
so, the tree is 13 ft and 4 inches tall.