The Total solution for NCERT class 6-12
ABC and DBC are two isosceles triangles on the same baseBC (see the given figure). Show that ∠ABD = ∠ACD.
Let us join AD.
In ΔABD and ΔACD,
AB = AC (Given)
BD = CD (Given)
AD = AD (Common side)
∴ ΔABD ΔACD (By SSS congruence rule)
⇒ ∠ABD = ∠ACD (By CPCT)