Is it correct or not that Slope / Gradient / Angles is referred to the linear relationship of straight-line in Linear Programming when we draw the material line; labour line; demand line in the graph?
What is the Objective line in Linear Programming (I couldn’t understand that in your lecture!)?
Whatever the total contribution turns out to be (and we obviously don’t know what it will be in advance) the angle of the line showing all combinations of the two products that will give that total contribution will be the same.
You cannot be asked to draw the line in the exam, but you are expected to understand the relevance of it and to be able to use it if you are given a graph with it on in the exam.