I think M<1 will equal 35 degrees.
To find the midpoint, Add the two X coordinates together then divde by two and then to the same with the Y coordinates:
X = -4 + 2 = -2 / 2 = -1
Y = 6+7 = 13/2
Midpoint = (-1,13/2)
22/32 = 100/x
22x = 100(32)
22x = 3200
x = 3200/22
x = 145.45 ft
Both have the same when simplified to its lowest point in the expression