USE PYTHAGORAS THEOREM SOLVE FAST PLS - Maths - Congruency of Triangles

Question

USE
PYTHAGORAS THEOREM SOLVE FAST PLS

Varun Rawat · Accepted Answer

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Let AD⊥BC
In ∆ADB and ∆ADC∠ADB = ∠ADC      90° each      AB = AC              Given       AD = AD              Common⇒∆ADB ≅ ∆ADC   RHS⇒BD = DC  CPCTSo, BD = DC = 12BC = 12×8 = 4 cmIn ∆ADC,    AD2 = AC2 - DC2       Pythagoras theorem⇒AD2 = 122 - 42⇒AD2 = 144 - 16 = 128⇒AD = 82 cmNow, area of ∆ABC = 12×BC×AD = 12×8×82 = 322 cm2

USE PYTHAGORAS THEOREM. SOLVE FAST PLS.