Answer:
x = 12 ft
Step-by-step explanation:
We know that by adding up all of the values of the sides, we will get the value of the perimeter. Using this information, we can set up an equation and simplify to find the variable.
16 + 20 + x + x = 60 <----- The sum of the sides is the perimeter
16 + 20 + 2x = 60 <------ Combine variables (x + x = 2x)
36 + 2x = 60 <----- Add 16 and 20
2x = 24 <----- Subtract 36 from both sides
x = 12 <----- Divide both sides by 2
