1, angular system: This is the most commonly used method, that is, dividing a circle into 360 degrees. In this method, the size of the angle can be expressed in degrees. For example, 30 degrees represents the112 part of a circle, that is, the position rotated 30 degrees clockwise from 0 degrees.

2. Curvature system: This is another commonly used method, and the angle is expressed by the ratio of arc length to radius. In the arc system, a circle is equal to 2π (about 6.28) radians. The main advantage of arc system is the arc length of circles with different radii, which makes the calculation of some problems involving radius and angle more convenient.

3. Secret bit system: this is a common angle representation in the military, which divides a circle into 6000 secret bits. In this method, the size of the angle can be expressed in dense digits. For example, 1 density represents the 1/6000 part of a circle, that is, the position of 1 density rotated clockwise from 0 density.

Application examples of degrees:

Application of 1. trigonometric function: In mathematics, degree is the basis of trigonometric functions (such as sine, cosine, tangent, etc.). ). These functions are widely used in various mathematical problems, such as solving angles in triangles and solving problems in polar coordinates. In addition, in the fields of signal processing and image processing, trigonometric functions are often used in discrete Fourier transform (DFT) and other algorithms.

2. Application in physics and engineering: In physics and engineering, degree is widely used to describe various physical quantities such as angle, speed and acceleration. For example, in mechanical engineering, it is often necessary to calculate the position and movement of objects in space, which requires the use of measurement units such as angle and radian. In physics, angular velocity, angular momentum and other physical quantities are also described by degrees.

3. Use in daily life: Degrees are also used in many places in daily life. For example, the geographical position is usually expressed by degrees on maps, and the wind direction and speed are also described by degrees in weather forecasts. In addition, when driving a vehicle, you also need to use measurement units such as angle and radian to adjust the driving direction and speed of the vehicle.