Answer:
If we look at ΔBDH, we notice that m∠BHG has to be 108 - 36 - 39 = 105°. Because x and ∠BHG are a linear pair we know that x = 180 - ∠BHG = 180 - 105 = 75°.
Well, we could make the number of lawns he mowed as 'L'
In this case, the total money that Gavin makes is 8.5L
I believe it is 960 inches. For the long triangles, I just made them a square so I multiplied base times height. For the small triangles, i did the same thing. Long triangles were 640, small triangles were 320