The perimeter of a square is 40 cm what is its length

10 cm

Step-by-step explanation:

A square has all four sides equal in length

Perimeter = 4 × side

40 = 4 × side

side = 10 cm

1. find the coordinates of b, c, e and f
b(-2,4)
c(1,1)
e(4,4)
f(6,2)

2. use the formula:
m=y2-y1/x2-x1

3. slope of bc
m=1-4/)
m=-3/3
m=-1

4. slope of ef
m=2-4/6-4
m=-2/2
m=-1

5. so both of the line segments have the slope of -1, have a nice day : d