A circle with centre \(O\) has two tangents \(TP\) and \(TQ\) drawn from an external point \(T\). Using the properties of tangents, demonstrate that \(\angle PTQ = 2\angle OPQ\).
 
Proof:
 
circle session iV prove that.png
 
We know that, the length of tangents drawn from to a circle are .
 
Therefore, \(TP = \)
 
So, \(\Delta TPQ\) is an triangle.
 
Therefore, \(\angle TPQ=\angle\)
 
\(TPQ = \) \(^\circ - \frac{1}{2}\theta\)
 
Also, we know that, the tangent at any point of a circle is to the through the point of contact.
 
\(\angle OPT=\)
 
\(\angle OPQ =\angle OPT-\)
 
\(\angle PTQ =2\)