- #1

- 2

- 0

##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.

Last edited by a moderator: