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lungoy

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##TA## and ##TD## are tangent line of circle ##ABCD## and ##TB \parallel DC##. Show ##A,E,D,T## are cyclic quadrilateral.

I know ##x=\angle TAD= \angle TDA = \angle ACD= \angle TEA##

And ##\angle ATD=180-2x##

But I don't know how to prove ##\angle AED=x##.

Or there's another easily method?

Thanks.

I know ##x=\angle TAD= \angle TDA = \angle ACD= \angle TEA##

And ##\angle ATD=180-2x##

But I don't know how to prove ##\angle AED=x##.

Or there's another easily method?

Thanks.

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