Question 941557
let x be the length of base 
length of other two sides = x-6
 perimeter ( sum of all 3 sides)= 84 ft
    x+x-6+x-6 = 84
   3x-12 = 84
   move -12 to the right
 3x=84+12
 3x=96
 divide with 3 on both sides
 {{{ 3x/3 =96/3}}}
  x=32
Length of base  = 32 feet