• Mar 13th 2010, 01:53 PM
disclaimer
Quadrilateral $ABCD$ is inscribed in a circle, where the tangents to this circle at points $B$ and $D$ intersect on the straight line joining $A$ and $C$. Show that:

$AB\cdot{CD}=AD\cdot{BC}$

• Mar 14th 2010, 09:34 PM
sa-ri-ga-ma
Quote:

Originally Posted by disclaimer
Quadrilateral $ABCD$ is inscribed in a circle, where the tangents to this circle at points $B$ and $D$ intersect on the straight line joining $A$ and $C$. Show that:

$AB\cdot{CD}=AD\cdot{BC}$