Analysis: According to the characteristics of a cuboid, the length of a group of four parallel sides in 12 sides is equal, and the length of two sides is 20cm, so the solution is as follows:

The formula is:

4x2+2x2+3x4+20

=8+4+ 12+20

=44 (cm)?

A: Tie up this gift box and prepare at least 44 cm ribbons.

This problem belongs to the problem of finding the sum of the sides of a cuboid. When solving, it is necessary to distinguish which edges are the sum of lengths.

Extended data:

Features of a cuboid:

① A cuboid has six faces, each of which is a rectangle (two faces may be squares), and the two opposite faces are exactly the same.

② A cuboid has 12 sides, and every four sides are equal (it can be divided into three groups according to the length of the sides).

③ The point where three sides intersect is called the vertex. A cuboid has eight vertices.

④ The edges intersecting at the same vertex are not equal, which is called the length, width and height of a cuboid. Taking the length, width and height of the same vertex as a group, it can be divided into four groups. ?