Step-by-step explanation:
Recall that

Therefore,

so


I think Its 6.............
slope = rise over run = y/x
A (-1,3) slope = 3/-1 = -3
B (1,2) slope = 2/1 = 2
C (-3,-1) slope = -1/-3 = 1/3
2 lines need to be negative reciprocals in order to be a right triangle
negative reciprocal of -3 is 1/3
so this is a right triangle
1860-1008=852
if you subtract the two numbers you get the difference