Q7 of 53 Page 156

is a median of ΔABC. AB2 + AC2 = 148 and AD = 7. Find BC.

AB2 + AC2 = 148


AD = 7


Applying Apploneus theorem :


AB2 + AC2 = 2(AD2 + BD2)


⇒ 148 = 2(49 + BD2)


⇒ BD2 = 74 – 49 = 25


⇒ BD = 5 units


BC = 2 × BD = 10 units


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