n : l : m = 4/5 : 3/5 : 1 = 0.8 : 0.6 : 1
m + n + l = 180
m + 0.8 * m + 0.6 * m = 180
2.4*m = 180
m = 75
l = 0.6 * 75 = 45
n = 0.8 * 75 = 60
n : l : m = 4/5 : 3/5 : 1 = 0.8 : 0.6 : 1
m + n + l = 180
m + 0.8 * m + 0.6 * m = 180
2.4*m = 180
m = 75
l = 0.6 * 75 = 45
n = 0.8 * 75 = 60