First get the length of the side the was cut (Hypotenuse).
We can use Pythagorean theorem: a^2+b^2 = c^2
a = 8, b = 3 = 1.5, c = ?
plug into forumla
8^2 + 3^2 = 73
a=8,
b=1.5,
c = sqrt( 73) or 8.5
Now add all sides together to get perimeter...
8+3+8.5 = 19.5
The perimeter of each sheet is 19.5in.
