Question no.5: 5. In the adjoining figure, the diameter CD of a circle with centre O is perpendicular to the chord AB. If AB=8 cm and CM=2 cm, find the radius of the circle. Share with your friends Share 1 Abhishek Jha answered this Dear student, Here is the solution of your asked query: Let the radius of the circle be r.OA=OC=rWe know that the perpendicular from center to the chord of the circle bisects the chord.So, AM=BM⇒AM=12AB=12×8=4cmAlso, OC=OM+CM=r⇒OM+2=r⇒OM=r-2 Now considering right triangle △AMO, we have;⇒OA2=OM2+AM2 {using Pythagoreous theorem}⇒r2=r-22+42⇒r2=r2+4-4r+16⇒4r-4=16⇒4r=20⇒r=5Therefore, radius of circle is 5 cm. Regards 2 View Full Answer