Angle between the sides measuring 119.62 meters and 110 meters is given by
Cos x = (119.62^2 + 110^2 - 42^2) / (2 x 119.62 x 110) = 24644.9444 / 26316.4 = 0.93648616
x = arccos(0.93648616) = 20.53
Now, let the length of the new ailse be l, then
sin 20.53 = l / 110
l = 110 sin 20.53 = 38.58 meters.