Sir i want to know how to prove the thales theorom

1.	Sir i want to know how to prove the thales theorom
Answer» Statement: If a line is drawn parallel to one side of a triangle, to interest the other two sides at indistinct points, the other two sides are divided in the same ratio.Given: -\xa0In\xa0△ABC,DE∥BC,,,,To prove:- AD/DB = AE/EC,,Construction:- BE and CD are joined. EF⊥AB\xa0and DN⊥AL,,\xa0are drawn.,,Proof:-,,ar(△ADE) = 1/2×AD×EF,, =1/2×AE×DN,,ar(△BDE) = 1/2×BD×EF,,ar(△CDE) = 1/2×EC×DN,,ar(△ADE)/ar(△BDE) = 1/2×AD×EF/1/2×BD×EF ........(1),,ar(△ADE)/ar(△CDE) = 1/2×AE×DN/1/2×EC×DN ........(2),,But, ar(△BDE) = ar(△CDE) ..............(3),,\xa0,as they are on the same base DE and DE∥BC,,\xa0from (1), (2) and (3) we get AD/DB = AE/EC,, Thank you.

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