To construct a triangle given its base , a base angle and the difference of the other 2 sides . given the base BC , a base angle b and the difference of the other 2 sides AB – AC YOU HAVE TO CONSTRUCT the triangle ABC .

If you want to see some example of construction plz click on this link:http://www.dronstudy.com/book/constructions-exercise-11-2-mathematics-ncert-class-9th/