Hot Air Balloon Angle with Ground

We had this question to do for homework which I am very confused with, can anyone help me?

Jennifer and Alex were flying a hot air balloon when they decided to calcutlate the straight line distance one the ground from Mathville to Trigtown. From a vertical height of 340m, they measured a 2degree angle of depression to Mathville, and a 3degree andlge of depression to Trigtown. The angle between these two sight lines, from the balloon, to the two towns was 80degrees. Find the distance along the ground from Mathville to Trigtown. Round to the nearest tenth of a metre.

It also asks for a 3-dimensional well labeled sketch, I dont understand how you would draw this in 3-D.

Sorry its such a big question but I really need help. Thank you so much in advance :D