Answer:
slope of BC = -

Explanation:
Given vertices A and B then the side BC is perpendicular to AB
calculate the slope m of AB using the slope formula
m =

let (x₁, y₁ ) = A (- 1, - 3 ) and (x₂, y₂ ) = B (6, 5 )
substitute these values into the formula for m
=
=
=

given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= -

the slope of side BC = -
