Why do the areas of different shapes differ even if their perimeter is same?

A rectangle that's 7 x 1 inches has a perimeter of 16 inches,

and its area is 7 square inches.

A rectangle that's 5 x 3 inches also has a perimeter of 16 inches,

but its area is 15 square inches.

A rectangle that's 6 x 2 inches also has a perimeter of 16 inches,

but its area is 12 square inches.

A square that's 4 inches on each side also has a perimeter of 16 inches,

but its area is 16 square inches.

A circle that's 16 inches around the outside also has a perimeter of 16 inches,

and its area is 20.4 square inches.

There's no reason why there has to be a connection between perimeter and area.