1, flat angle is an important concept in geometry, which means that two rays start from the same point and their included angle is 180. In plane geometry, a straight angle has the following properties and characteristics: the size of a straight angle: the size of a straight angle is equal to 180, which is a fixed value and will not change because of different observation angles.

2. Composition of a right angle: A right angle consists of two right angles, and the size of each right angle is 90. Therefore, a right angle can be regarded as the superposition of two right angles. Complementary angle of flat angle: the angle complementary to flat angle is called complementary angle, and the sum of other angles and flat angle is equal to 180. For example, the sum of a straight angle and a right angle is equal to the sum of a complementary angle and a right angle.

3, the nature of the flat angle: the flat angle has the following properties: the degree of the flat angle is a fixed value, not affected by the observation angle. The degree of a right angle is twice that of a right angle. The degree of a right angle is twice that of an acute angle. The degree of a right angle is half that of an obtuse angle. Application of flat angle: Flat angle is widely used in geometry.

The importance of a degree is as follows:

1, degree is a very important concept in mathematics, indicating the size of an angle. Degree is the basic knowledge of geometry in mathematics, and it is also the basis of trigonometric functions, complex numbers and other mathematical fields. In real life, degrees are also widely used, such as engineering, medicine, economics and other fields. The concept and calculation method of degree are very important for mathematics learning and application.

2. When learning mathematics, we need to understand the concept, nature and calculation method of degree, and master the application skills and methods of degree, so as to better solve various mathematical problems. At the same time, in real life, the application of degrees is everywhere, such as measuring angles and calculating angles.

3. Degree is a very important concept in mathematics, which is not only widely used in geometry, but also the basis of other mathematical fields. Learning degree and the calculation method of learning degree are very important for mathematics learning and application. Degree also plays a key role in physical science. For example, in physics, angle is the basis of studying concepts such as motion, force and energy.