18.0
Step-by-step explanation:
The distance formula to find the distance between two points P(a,b) and Q(c,d) is :_
From the graph, the coordinates of ΔCDE are C(-3,1) , D(1,4) and E(3,-2).
Then, length of CD :-
Length of DE :-
Length of EC :-
Now, the perimeter of triangle :_
Hence, the perimeter = 18.0 units