If AD is an altitude of an isosceles triangle ABC in which AB = AC. Then:
Answer & explanation
Correct answer: option 1
In ΔABD and ΔACD,
∠ADB = ∠ADC = 90°
AB = AC (Given)
AD = AD (Common)
∴ ΔABD ≅ ΔACD (By RHS congruence condition)
BD = CD
We can also use AAS criteria as ∠ABD and ∠ACD are equal (Sides AB and AC are equal)