What are the characteristics of the ball and what are the main characteristics of the ball

The characteristics of the ball are:

1. The line between the center of the sphere and the center of the cross-section circle is perpendicular to the cross-section.

2. The distance d from the center of the sphere to the cross-section has the following relationship with the radius r of the ball and the radius r of the cross-section: r = r d.

3. The circle that is cut by the plane of the sphere through the center of the sphere is called the great circle, and the circle that is intercepted by the section that does not pass through the center of the sphere is called the small circle.

4. On the sphere, the length of the shortest line between two points is the length of a bad arc between these two points of the great circle passing through these two points, and we make this arc long.

This is called the spherical distance of two points.

By his rugby player-like body. The basic skills are average, and he mainly relies on his body to eat his opponent.

3. The line between the center of the sphere and the center of the cross-section circle is perpendicular to the cross-section.

2. Use a plane to intercept a ball, and the cross-section is a circular surface.

3. The sphere is on any plane.

Orthographic projections are all equal-sized circles, and the diameter of the projected circle is equal to the diameter of the sphere.

4. The distance d from the center of the sphere to the cross-section has the following relationship with the radius r of the ball and the radius r of the cross-section: r 2 = r 2-d 2.

On a sphere, the length of the shortest line between two points is the length of a bad arc between these two points of the great circle passing through these two points, and this arc length is called the spherical distance between the two points.

"In the space of a ball with the same length. Set definition: (1) The set of points whose distance from the fixed point in space is equal to or less than the fixed length is called a sphere, referred to as a sphere.

2) The set of points whose distance from a fixed point in space is equal to a fixed length is called a sphere, that is, the surface of a sphere. (3) The center of the ball at a fixed point, and the radius of the ball at a fixed length.

The surface of the sphere is a surface, and this surface is called a sphere.

The semicircle takes its diameter as the axis of rotation, and the surface formed by rotation is called a spherical surface.

The geometry enclosed by a sphere is called a sphere, or sphere for short.

The center of a semicircle is called the center of the sphere.

The line segment connecting the center of the sphere to any point on the surface of the sphere is called the radius of the sphere.

The diameter of the ball is the line segment that connects two points on the sphere and passes through the center of the sphere.

Use a plane to cut a ball, and the cross-section is a circular surface.

The ball is easy to roll.

The straight line with the diameter of the semicircle is called the axis of rotation, and the rotating body formed by the rotation of the semicircle surface is called the sphere, referred to as the ball. The center of a semicircle is called the center of the sphere. The radius of the semicircle is called the radius of the ball.

The diameter of the semicircle is called the diameter of the ball. Representation of the ball: Represented by a letter indicating the center of the ball.

The type of ball

There are many, many types of balls, including football, handball, basketball, volleyball, badminton, tennis, golf ball.

Ice hockey, baseball, softball, rattan, shuttlecock, table tennis.

Billiards, cricket, squash, krona, rugby.

Hockey, water polo, polo, bowling, fitness ball, croquet, pinball, and many more.

1. Badminton. Badminton is mainly played by the fit of the hand and the shuttlecock, and the amount of exercise is quite large, which is suitable for indoor or windless outdoors.

2. Table tennis. Table tennis is China's national sport.

What is important is the tacit understanding between the hand and the racket and the ability of the eyes to adapt to the ball.

3. Basketball. Playing basketball well depends on the team ability of a team.

Rather than an individual, playing basketball well can also exercise our quality in all aspects, which is a good ball game.

4. Volleyball. Playing volleyball relies on gestures and movements, and to play volleyball well, you must practice the kung fu in place.

5. Tennis. The amount of exercise in tennis is also very large, striding down, striding exercise.

6. Bowling. This ball game is very easy to build personal self-confidence and also easy to build our arm strength, which is very good.

The main features of the sphere:

1. The distance from any point on the spherical surface to the center of the sphere is equal to the radius of the grip.

2. The cross-section of the ball is a circle.

3. Three-dimensional graphics with and only one continuous surface.

4. The orthographic projection on any plane is an equal-sized circle, and the diameter of the projection circle is equal to the diameter of the sphere.

5. The line between the center of the sphere and the center of the cross-section circle is perpendicular to the cross-section.

6. The distance d from the center of the sphere to the cross-section has the following relationship with the radius r of the ball and the radius r of the cross-section: r 2 = r 2-d 2.

The cross-section of the ball has the following properties:

1. The line between the center of the sphere and the center of the cross-section circle is perpendicular to the cross-section.

2. The distance d from the center of the sphere to the cross-section has the following relationship with the radius r of the ball and the radius r of the cross-section: r 2 = r 2-d 2.

The circle that is cut by the flat section of the sphere through the center of the sphere with the imaginary surface is called a great circle, and the circle that is cut by the section that does not pass through the center of the sphere is called a small circle.

On a sphere, the length of the shortest line between two points is the length of the inferior arc between these two points of the great circle passing through these two points.

The line between the center of the sphere and the center of the section is perpendicular to the section.

What balls? Most of them are not all round.