Question

Point B ∈ AC . Find the length of segments ABand BC if AC = 20 cm and AB:BC = 3:2

Answer 1

AB:BC = 3:2

so AB=3/2BC

AB+BC=AC=20

substitute 3/2BC+BC=20

5/2BC=20

BC=2*20/5=8

AB=3/2*8=12

Answer 2

Apply a:b=c:d as a/b=c/d

AB:BC = 3:2 is AB/BC=3/2

AB=3/2*BC

AC=20=AB+BC

So 20=3/2*BC+BC

1 3/2BC=20

BC=8cm

AB=20-8=12cm