The length of a circle, also called circumference, can be calculated by the formula: circumference = 2πr r r.

Specific introduction:

Where π is a mathematical constant, which is approximately equal to 3.14159; R is the radius of the circle.

So to calculate the circumference of a circle, you need to determine the radius of the circle first, and then substitute the radius into the above formula to calculate. For example, if the radius of a circle is 5cm, its circumference is 2x3.14159x5 = 31.4159cm. ..

Circle profile:

A circle is a geometric shape, which consists of all points on a curve equidistant from the center. This equidistant distance is called radius, which is usually represented by the letter R. The curve of a circle is called a circle, or a circle.

Here are some basic concepts related to circles:

Center of circle:

The center point of a circle, usually expressed as O.

Radius:

The distance from the center of the circle to any point on the circumference is usually expressed as r.

Diameter:

A line segment passing through any two points of the center of the circle and both of which are on the circumference. The diameter is twice the radius.

Application of circle:

1, Architecture and Urban Planning:

Circular architecture and urban design are common in historical buildings and modern buildings. For example, the circular tower, circular building structure and circular square in the city center.

2. Transportation:

Traffic around the island (also known as roundabout or roundabout) is a common traffic planning and design, aiming at improving the smoothness and safety of traffic.

3. Aerospace:

The cockpit, aero-engine, conical part and so on of the spacecraft all adopt circular design.

4. Electronic equipment:

Many electronic devices and instruments use circular designs, such as circular display screens and circular control buttons.

5. Piping and piping system:

Circular pipelines and circular containers are widely used in industrial and construction fields, such as water supply pipelines, oil and gas pipelines, sewage pipelines and so on.

6, automation and robotics:

Many robots and automation systems use round joints and wheels to achieve flexible movement and rotation.

7. Circular motion:

Sports and physical education class often involve circular runways or venues, such as track and field, basketball court and football field.