In the adjoining figure, AB = 10 cm, BC =15 cm AD : DC = 2 : 3, then find the value of∠ABC.
40º
Clearly, ADDC = 23 and ABDC = 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∘