The length of wood needed for triangle DFG is 54 inches
Start by calculating the side length DG in triangle DFG
The side lengths of DFG are three times the corresponding side length of ABC
So, we have:
[tex]DG = 3 \times AC[/tex]
[tex]DG = 3 \times 7\ in[/tex]
[tex]DG = 21\ in[/tex]
The perimeter of triangle DFG is then calculated as:
[tex]P = DF + FG + DG[/tex]
This gives
[tex]P = 15 + 18 + 21[/tex]
[tex]P = 54[/tex]
Hence, the length of wood needed is 54 inches
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