The length integral of the edge around a finite area is called perimeter, which is the length of a closed graph. The perimeter of a polygon is also equal to the sum of all the edges of the graph.

The formula of common figure perimeter:

1, circle: C=πd=2πr (d is diameter, r is radius, π).

2. The perimeter of the triangle is C = a+b+c(abc is three sides of the triangle).

3. Quadrilateral: C=a+b+c+d(abcd is the side length of quadrilateral)

4. Special: rectangle: C=2(a+b) (a is long and B is wide)

5. Square: C=4a(a is the side length of the square)

Extended data:

Area is a quantity indicating the degree of a two-dimensional figure or shape or plane layer in a plane. A surface region is a simulation on a two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness, which is necessary to form a model of shape, or the amount of paint required to cover a surface with a single coating. It is a two-dimensional simulation of curve length (one-dimensional concept) or solid volume (three-dimensional concept).

Area and perimeter

If it is a triangle with the same area, the perimeter of an equilateral triangle is the shortest; If it is a quadrilateral with the same area, the perimeter of the square is the shortest; If pentagons with the same area are used, the perimeter of a regular pentagon is the shortest.

If you use any polygon with the same area, the circumference of a regular circle is the shortest. Perimeter can only be used on two-dimensional figures (planes and surfaces), and three-dimensional figures (solids) such as cylinders, cones and spheres can't express their boundary size by perimeter, but by total surface area. Total surface area = the total area of all sides of a solid.