∆ABC is an isosceles triangle with AB = AC = 10 cm,

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∆ABC is an isosceles triangle with AB = AC = 10 cm, AD = 8 cm is the median on BC from A. The length of BC is

1. 8 cm
2. 12 cm
3. 10 cm
4. 6 cm

Correct Option: B

We draw a figure of an isosceles triangle ABC with AB = AC = 10 cm, AD = 8 cm is the median on BC from A ,

D, is the mid–point of BC.
Given that , AB = AC = 10 cm.
AD ⊥ BC
From ∆ ABD,
BD = √AB² - AD²
BD = √10² - 8²
BD = √100 - 64
BD = √36 = 6 cm.
∴ BC = 2BD = 2 × 6 = 12 cm.