Bantu saya, jangan pelit dong, saya sangat butuh bantuan kalian, trimsss

AB/DE = 3/4
AB/20 = 3/4
4AB = 20 x 3
4AB = 60
AB = 60/4
AB = 15 cm

CD/BC = DE/AB
CD/12 = 20/15
CD/12 = 4/3
3CD = 4 x 12
3CD = 48
CD = 48/3
CD = 16 cm

*semoga membantu. sukses selalu ^_^