\(XY\) and \(XZ\) are two equal chords of a circle. Verify that the bisector of the angle \(YXZ\) passes through the centre of the circle.
 
Explanation:
 
\(XY\) and \(XZ\) are two equal chords whose centre is \(O\).
 
Now, Join \(YZ\).
 
Draw bisector \(XD\) of \(∠YXZ\)
 
Therefore, \(∠YXD=∠ZXD\)
 
circle session 4 ques 4 Image 3 .png
 
In \(△YXO\) and \(△ZXO\),
 
\(XY = \)   (given)
 
\(∠YXO=∠\) (by construction)
 
\(XO =\)   []
 
Therefore, \(△YXO≅△ZXO\) []
 
That is, \(YO = ZO\) [by ] and
 
\(∠YOX=∠ZOX\) [by ]
 
Also, \(YO = ZO\) and \(∠YOX=∠ZOX=\)\(^°\)
 
Thus, \(XO\) is the perpendicular bisector of the chord \(YZ\).
 
Therefore, the bisector of \(∠YXZ\) passes through the centre \(O\).
 
That is., \(XD\) passes through the centre \(O\).
 
Hence proved.