Question 513039
Perimeter = sum of the sides
x = a + b + c     x represents the perimeter
x=10ft + 1/3x +1/2x
-10ft + x = 10ft – 10ft + 1/3x +1/2x
-10ft + x –x =-x+1/3x+1/2x
-10ft = -6/6x+2/6x+3/6x
 -10ft = -1/6x
-6(-10ft) = -6(-1/6x)
  60ft = x  .. therefore the perimeter is 60ft.

Check:
x=10ft + 1/3x +1/2x
60ft = 10ft + 1/3(60ft) + ½(60ft)
60ft = 10ft + 20ft + 30ft
60ft = 60ft