Question

radius of a circle is 5 cm. the leghth of chord is 8cm find the distance of chord from the centre

Answer 1

Let O be the centre of the circle and AB be the chord.
Join OA.
Draw OC perpendicular to AB.

AC=1/2AB (Perpendicular from the centre bisects the chord)
     = 4 cm
OA=5 cm (Radius)

Triangle OCA is right angled,
... OC​2 =OA​2 - AC2 (Pythagoras Theorem)
            =52 - 42
             =25 - 16
             =9
 ...   OC= 3cm
 

Answer 2

This is your answer