the perimeter is the sum of the lengths of the sides of a flat geometric figure. The word comes from the Greek peri and meter. The term can be used both for the distance or length, and for the length of the contour of a shape.
The perimeter of a polygon is calculated by adding the lengths of all its sides. Thus, the formula for the triangles is P: A + B + C, where A, B and C are the lengths of each side. For quadrilaterals, the equation is P: A + B + C + D. More generally, for a polygon of N