Divide 180 in the ratio 4:5:9
4+ 5 + 9 = 18
So you would need to share 180 to 18 groups equally
180/18 = 10
1st group = 10 * 4 = 40
2nd group = 10 * 5 = 50
3rd group = 10 * 9 = 90
Double check: 40 + 50 + 90 = 180