in right angled triangle BAC,angle BAC is 90 segment AD,BE and CF are medians . Prove 2[AD2+BE2 +CF2]=3BC2
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Draw right angle triangle ABC,
draw medians. AD, BE, CF. Now Join DF.
Since D and F are midpoints of sides AB and BC, DF will be parallel to AC and is equal to 1/2 AC.
ADF, ABE, AFC are all right angle triangles.
LHS = 2 (AD² + BE² + CF² )
= 2 [ (AF² + DF²) + (AB² + AE²) + (AF² + AC²) ]
= 2 [ (AB²/4 + AC²/4) + (AB² + AC²) + (AC²/4 + AB²/4) ]
= 2 [ BC² /2 + BC² ]
= 3 ( BC² ]
draw medians. AD, BE, CF. Now Join DF.
Since D and F are midpoints of sides AB and BC, DF will be parallel to AC and is equal to 1/2 AC.
ADF, ABE, AFC are all right angle triangles.
LHS = 2 (AD² + BE² + CF² )
= 2 [ (AF² + DF²) + (AB² + AE²) + (AF² + AC²) ]
= 2 [ (AB²/4 + AC²/4) + (AB² + AC²) + (AC²/4 + AB²/4) ]
= 2 [ BC² /2 + BC² ]
= 3 ( BC² ]
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