Prove that the triangle formed by a chord and the centre of the circle is isosceles.
Proof:
Let \(PQ\) be the chord and \(O\) be the centre of the circle.
Here, \(OP\) and \(OQ\) are of the circle.
Thus, \(OP\) and \(OQ\) are .
Hence, the triangle \(POQ\) has equal sides.
Therefore, the triangle formed by a chord and the centre of the circle is .