since FGH is an equilateral triangle, all its sides are equal, therefore
[tex]FG=GH=FH[/tex]
then
[tex]\begin{gathered} x+5=3x-9 \\ x+5-5=3x-9-5 \\ x=3x-14 \\ x-3x=3x-14-3x \\ -2x=-14 \\ -\frac{2x}{-2}=-\frac{14}{-2} \\ x=7 \end{gathered}[/tex]
answer: x = 7
for FG:
[tex]FG=x+5=7+5=12[/tex]
answer: FG = 12
for GH:
[tex]GH=3x-9=3(7)-9=21-9=12[/tex]
answer: GH = 12
for FH:
[tex]FH=2x-2=2(7)-2=14-2=12[/tex]
answer: FH = 12
