How long is DE rounded to the nearest tenth? Enter your answer in the box.

Answer:
7.2
Step-by-step explanation:
Length AB is the difference of the horizontal dimensions shown:
AB = GF = EF -EG
AB = 12 -7 = 5
The triangles in the figure are all similar, so we have ...
DE/DC = CB/AB
DE/12 = 3/5
DE = 12(3/5) = 7.2