In the adjoining figure, AB=10 cm, BC=15 cm and AD:DC=2:3, then ∠ABC is equal to
40º
Clearly, ADDC=23 and ABBC=1015=23
So, ADDC=ABBC
Thus, BD divides AC in the ratio of the other two sides.
∴ BD is the bisector of ∠B.
Now, ∠CBD=180∘−(130∘+30∘)=20∘
∠B=2(∠CBD)=40∘