Respuesta :
Answer:
6.4
Step-by-step explanation:
9.8 + 10.9 + x = 27.1
20.7 + x = 27.1
x = 6.4
We know perimeter of triangle=sum of sides
[tex]\\ \sf\longmapsto 9.8+10.9+x=2.71[/tex]
[tex]\\ \sf\longmapsto x+20.7=2.71[/tex]
[tex]\\ \sf\longmapsto x=2.7-20.7[/tex]
[tex]\\ \sf\longmapsto x=|-18|[/tex]
[tex]\\ \sf\longmapsto x=18ft[/tex]