The definition of perimeter is the integral of the length around the whole edge of this graphic area, which is simply the whole length of one week of the edge of a graphic.

Every different figure has a different method to calculate the perimeter. For example, some quadrangles are common, and their perimeters are the sum of the lengths of all sides, while the circumference of a circle is the formula: π times the diameter of the circle. Perimeter has an important premise, that is, only closed graphics can calculate perimeter, and more complex graphics can be divided and calculated.

formula

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)