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What letter is used to indicate the circumference?
C stands for circumference.

2.l stands for arc length and is also used to represent chord length. 3.s stands for area. 4.v stands for surplus products. The length integral of the edge around a finite area is called the perimeter, which is the length of a graph.

The circumference is represented by the letter C. Let the upper bottom length of the trapezoid be A, the lower bottom length be B, the two waist lengths be E and D respectively, and the circumference be C. Then the formula of the circumference of the trapezoid is C=a+b+c+d, which is usually represented as: upper bottom+lower bottom+waist+waist. Calculation formula of perimeter: circle: c = π d = 2π r (d is diameter, r is radius, π) The perimeter of a triangle is c = a+b+c (ABC is three sides of the triangle). Quadrilateral: c = a+b+c+d (ABCD is the side length of quadrilateral). Special: rectangle: c = 2 (a+b) (a is long and b is wide) square: c = 4a (a is the side length of a square).

Polygon: c = sum of all sides.

The circumference of the sector: c = 2r+nπ r ÷ 180 _ (n = central angle) = 2r+kr (k = radian). The circumference of the earth was first calculated in the history of circumference: Eratosthenes in ancient Greece calculated the circumference of the earth with simple measuring tools more than 2,000 years ago.