Question

In the given figure, AB = BC and AC = CD. Prove that BAD : ADB = 3 : 1.

Answer 1

Step-by-step explanation:

Let ∠ADB=x

In △ACD,AC=CD

⇒∠CAD=∠CDA=x

and, ∠ACB=∠CAD+∠CDA=x+x=2x

⇒∠BAC=∠ACB=2x.(∵ In ABC,AB=BC)

∴∠BAD=∠BAC+∠CAD

=2x+x=3x

And,

∠ADB

∠BAD

=

x

3x

=

1

3

i.e., ∠BAD:∠ADB=3:1

{ HENCE PROVED }