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In the givernAF-4AD2-3AC2.fgure, ABC is a right trangle, right angled at C and D is the mid-pount of BC. Prove that |
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Answer» ABC is a right angled at B and D is the midpoint of BC. In ∆ABD AD²= AB²+BD²…………(1)[By Pythagoras theorem] In ∆ ABCAC²= AB²+BC²…………(2) From equation (1) AD²= AB²+ (BC/2)²[D is the midpoint of BC] AD²= AB²+ BC²/4AD²= AB²/1+ BC²/44AD²= 4AB²+ BC²BC²= 4AD²-4AB²…………….(3)Using the value of BC² in eq. 2 AC²=AB²+4AD²-4AB² AC²=AB²-4AB+4AD²AC²= 4AD²-3AB² |
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