Question 5:

Answer finished:

This part of the extended data mainly examines the knowledge points around the perimeter:

The integral of the length of the edge around a finite area is the perimeter, which is the length of a graph. The perimeter of a polygon is also equal to the sum of all sides of a graph, the perimeter of a circle =πd=2πr (d is the diameter, R is the radius, π), and the perimeter of a sector = 2R+nπR÷ 180? (n= central angle) = 2R+kR (k= radian).

Formula:

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

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

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

Special: rectangle: C=2(a+b) (a length b width)

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

Polygon: C= sum of all sides.