System of linear estimates/2 variables/Solution set is triangle/Exercise

Let

${}a_{1}x+b_{1}y\geq c_{1}\,,$

${}a_{2}x+b_{2}y\geq c_{2}\,,$

${}a_{3}x+b3y\geq c_{3}\,,$

be a system of linear inequalities, whose solution set is a triangle. How does the solution set look like, when we replace one inequality ${}\geq$ by ${}\leq$?

Create a solution