Given:
A point (-4,y) lies on the line BC of the triangle.
The objective is to find the value of y.
Step-by-step explanation:
Consider two points of the straight line BC of the triangle ABC.

The slope of the straight line can be calculated as,

On plugging the coordinates in equation (1),

To find y:
Now, consider the given coordinate and the point C.

On plugging the obtained values in the equation of slope,

Hence, the value of y is 1.