In the given figure, OD bisects AB. If AB = 8 cm and the radius of circle is 5 cm, then OD is equal to
Given: AB = 8 cm and OD bisects AB.
So, AD = DB = 4 cm.
∠ODB=90∘ [Line through centre that bisect the chord is perpendicular to chord.]
So, OB2=OD2+DB2 [∵ΔODB is right angled triangle.]
OD2=OB2−DB2
OD2=(5)2−(4)2 [OB is radius]
OD2=25−16
OD2=9
OD = 3 cm