A rectangular piece of paper is folded horizontally and vertically, and you will find that the length of the two long sides of the rectangle is half of the original length, and the length of the two short sides is half of the original length.

Because after vertical folding, the long side of the rectangle is reduced by half and becomes the original 1/2.

Similarly, after transverse folding, the short side is also reduced by half, becoming the original 1/2.

Extended data:

Rectangle, a mathematical term, is a parallelogram with right angles called rectangle. It is also defined as a parallelogram whose four corners are right angles. At the same time, the square is a special rectangle and a diamond.

Definition of rectangle length and width:

The first opinion: the long side of a rectangle is called long and the short side is called wide.

The second opinion: the same direction as the horizontal plane is called length, and the opposite is called width. The length and width of a rectangle are relative, and it cannot be absolutely said that "it is longer than the width", but it is customary to say that the long one is long and the short one is wide.

The nature of the rectangle:

(1) The two diagonals are equal;

(2) Two diagonal lines are equally divided;

(3) Two groups of opposite sides are parallel respectively;

(4) Two groups of opposite sides are equal respectively;

(5) All four corners are right angles;

(6) There are two symmetrical axes (there are four squares);

(7) Unstable (easily deformed);

(8) The quadrilateral obtained by connecting the midpoints of each side of the rectangle in turn is a diamond.