1993 IMO Problems/Problem 2
Revision as of 10:32, 21 November 2017 by William122 (talk | contribs) (Created page with "Let <math>D</math> be a point inside acute triangle <math>ABC</math> such that <math>\angle ADB = \angle ACB+\frac{\pi}{2}</math> and <math>AC\cdot BD=AD\cdot BC</math>. \rene...")
Let 
be a point inside acute triangle 
such that 
and 
.
\renewcommand{\theenumi}{\Alph{enumi}}
\begin{enumerate}
\item Calculate the ratio \frac{AC\cdot CD}{AC\cdot BD}
\item Prove that the tangents at 
to the circumcircles of 
and 
are perpendicular.
