The given figure has a length of 18 cm and width of 24 cm. A rectangle of length 8.6cm has been cut out, however, the question is asking to find the perimeter, or distance around the figure. The overall rectangle still has a perimeter of 18 + 18 + 24 + 24 = 84. However, now it also has two additional sides of 8.6cm each, so 8.6 + 8.6 = 17.2.
