The slope of four sides are as given, AB ⇒-3, BC⇒
, CD⇒-3, DA⇒

Explanation:
Given,
A = (-3,1)
B = (-2,-2)
C = (2,3)
D = (0,3)
Formula
The value of slope(m) of two given points (x1, y1) and (x2, y2) is
m=

- The slope of AB is =
=
= -3
- The slope of BC is =
=

- The slope of CD is =
=
= -3
[For finding the slope of AB we take, B as (x2,y2) and A as (x1, y1)
These same this follow for every sides]