Answer:
Step-by-step explanation:
the balloon starts at (10, 0 )
it ends at 16,0)
in the middle it's at between 10 and 16 , so say about 13, where it reaches 27
so in the middle it's (13,27)
so ( 11, 9)
(12, 18)
got 13
(14, 18)
(15, 9)
got 16
:P