A: This area is 452. 16 square centimeters.

(2)452. 16+3. 14×( 12÷2)2×2,

=452. 16+3. 14×36×2,

=452. 16+226.08,

=678.24 (square centimeter).

Answer: To make this gift box, you must use at least 678.24 square centimeters of iron.

(3)3. 14×( 12÷2)2× 12,

=3. 14×36× 12,

= 1356.48 (cubic centimeter).

A: The volume of this gift box is 1356.48 cubic centimeters.

(4)( 12+ 12)×4+20,

=24×4+20,

=96+20,

= 1 16 (cm).

Answer: It takes 1 16 cm to tie this gift box.

So the answer is: 288,565,438+04.08, 1356.48, 1 16.