Think about the circles and try to draw the diagram.

The distance of the chord from the centre is equal to the length of the perpendicular.

The line drawn through the centre of a circle to bisect a chord is perpendicular to the chord.

What have you learnt about angles subtended by equal chords at centre of the circle.

Draw the circle and think what needs to be done.

Draw three non-collinesr points. Now try to draw circles passing through these points.

Draw the diagram and let x be the distance of the chord from the centre of the small circle.