pada gambar di bawah,jika x : y = 3 : 2,maka besar

→ x = 3p
→ y = 2p

x + y = 120
3p + 2p = 120
5p = 120
p = 120/5
p = 24

x = 3p
x = 3(24)
x = 72

BAE = 180 - x
BAE = 180 - 72
BAE = 108˚