Circumcircle is tangent to the circumcircle

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Kazi_Zareer
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Circumcircle is tangent to the circumcircle

Unread post by Kazi_Zareer » Fri Aug 05, 2016 1:21 pm

In $\triangle ABC$,$AB>AC$,let $H$ be $\triangle ABC$'s orthocenter,$M$ be $BC$'s midpoint.point $S$ is on $BC$ satisfies $\angle BHM=\angle CHS$.Point $P$ is on $HS$ so that $AP \perp HS$
Prove that the circumcircle of $\triangle MPS$ is tangent to the circumcircle of $\triangle ABC$
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asif e elahi
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Re: Circumcircle is tangent to the circumcircle

Unread post by asif e elahi » Fri Aug 05, 2016 2:07 pm

Step 1: Let $\overrightarrow{MH}\cap \bigodot ABC=U$. Prove $U\in \bigodot ABC$.
Step 2: Let $\overrightarrow{AH}\cap \bigodot ABC=T$. Prove $T\in US$.

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Raiyan Jamil
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Re: Circumcircle is tangent to the circumcircle

Unread post by Raiyan Jamil » Sat Aug 06, 2016 1:19 am

Invert circle $MPS$ and circle $ABC$ w.r.t. circle with diametre $BC$..... using miquel, radical axis the rest is easy....
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