Answer:
^two dimentional figure with algebra^
the perimwter from triangle is:
s1 + s2 + s3
ok, enter:
s1 + s2 + s3= 369
x + (8x -5) + 2x = 369
x + 8x - 5 + 2x = 369
group according to the same variable
(x + 8x + 2x) + (-5)=369
11x + (-5)=369
11x - 5= 369
11x = 369 + 5
11x =374
x =374 : 11
x = 34
ok, subtituted:
s1= x
=34 feet
s2= 8x - 5
=8(34) - 5
=272 - 5
=267 feet
s3= 2x
=2(34)
=68 feet
FINALLY FOUND, MODERAT0R!!!!