Help does anyone know how to find z using circle theorem

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)

500

Not a smart person, but pretty sure i need a diagram to solve (not enough information given to solve)

  example you can find the perimeter by addig all of its respective sides as such: (12+x)+(12+x)+(7+y)+(7+y).  adding like terms will result in   2x+2y+38    if you chose  xy+7x+12y+84, you multiplied the two sides to find the area.  if you chose  x+y+19