First, the geometric characteristics of the cover of mathematics textbooks

The cover of a math textbook is a rectangle with four corners. Every angle is a right angle, that is, the degree of every angle is 90 degrees. This is because a rectangle is defined as a quadrilateral with equal opposite sides and four corners at right angles. Therefore, the cover of mathematics textbooks has rectangular geometric characteristics.

Second, the definition and nature of right angle

A right angle is the angle between two adjacent sides that are perpendicular to each other, and its degree is 90 degrees. In plane geometry, a right angle is a special angle, which has the following properties:

1, the two sides of the right angle are perpendicular to each other, that is, their included angle is 90 degrees;

2. The included angles between the two sides of the right angle and the hypotenuse are 45 degrees respectively;

3. Both sides of the right angle are equal;

Both sides of the right angle are parallel.

Third, the application of right angle in the cover of mathematics textbooks

The right angle on the cover of mathematics textbooks not only has geometric characteristics, but also has practical application value. For example, when solving geometry problems, we can use the nature of right angles for calculation and reasoning. In addition, right angles are widely used in architecture, design and other fields, such as right triangle theorem and pythagorean theorem.

The origin of mathematics

First, mathematics in ancient civilization

The origin of mathematics can be traced back to ancient civilization. In ancient Egypt, Babylon, India and other civilizations, people have begun to use simple calculation tools, such as abacus and ruler. In addition, they also studied some basic geometric shapes, such as triangles, squares and circles.

Second, the development of ancient Greek mathematics

Ancient Greece is an important period for the development of mathematics. Pythagorean school put forward the famous Pythagorean theorem, that is, the square of hypotenuse of right triangle is equal to the sum of squares of two right angles. Euclid wrote Elements of Geometry, which systematically summarized the geometric knowledge at that time. In addition, there were many famous mathematicians in ancient Greece, such as Archimedes and Ptolemy.

Third, the stagnation of medieval mathematics.

In the Middle Ages, due to the influence of religion, the development of mathematics in Europe came to a standstill. However, scholars in the Arab region have made many important mathematical achievements in this period, such as the development of algebra and the study of trigonometric functions.