The one which has the greatest initial DOWNWARD velocity which is ball 4
Why?
Because if you draw a line from A to D to make a triangle AED, then triangle all angle add up equal 180.
1.75
4 x 1.75 = 7 so that is the answer
Since the lines are perpendicular the opposite angle of labeled is also 60° and so would the two angles on the the lower just opposite way therefore 8x-4=60
-4 -4
8x=56
/8 /8
X=7