Here is the answer from SparkNotes
http://www.sparknotes.com/math/algebra2/operationsonfunctions/section3.rhtml
Answer:

Step-by-step explanation:
Given 2 similar figures with ratio of sides = a : b, then
ratio of areas = a² : b²
Here ratio of sides = 52 : 68 = 13 : 17 ← in simplest form, thus
ratio of areas = 13² : 17² = 169 : 289 = 
What kind of problems or what are you trying to ask?
P=4s
s=p/4
a=s^2, using s found above
a=p^2/16, we were told that p=40 so
a=40^2/16
a=100 in^2