First, we take into consideration the longest distance from one corner of the notebook to another. That is the diagonal of the notebook,
d² = (8.5 in)² + (11 in)² = 13.90 inches
For 400 miles, we convert this to inches using the original scale.
(400 miles)(1 in/20 miles) = 20 in
Since, the longest distance is only 20 inches, therefore it is impossible for Petra to represent the distance.
An example of scale that Petra could use is 1in = 40 miles.
