Each page of a book measures 12 inches by 8 inches. The cover extends beyond the shorter side one half inch in both directions.

What is the perimeter of the book's cover in inches?

Based on the given condition above for the dimensions of the cover, the length is 12 inches and the new width is 9 inches. Perimeter is twice the sum of the dimensions,

P = 2 x (L + W)

Substituting the known dimensions,

P = 2 x (12 in + 9 in) = 42 in

Therefore, the perimeter of the cover is 42 inches.