Answer:
80 ft
Step-by-step explanation:
We are given two similar triangles ABC and DFG
When two triangles are similar then the ratio of their corresponding sides are equal.
[tex]\frac{AB}{DF}=\frac{BC}{FG}=\frac{AC}{DG}[/tex]
AB=4 ft
BC=5ft
AC=7 ft
DF=20 ft
FG=25 ft
[tex]\frac{4}{20}=\frac{5}{25}=\frac{7}{DG}[/tex]
[tex]\frac{4}{20}=\frac{7}{DG}[/tex]
[tex]DG=\frac{7\times 20}{4}=35 ft[/tex]
Perimeter of DFG=DF+FG+DG=20+25+35=80 ft
Hence, she would need fence for triangle DFG=80 ft
