Two circles are concentric. A chord of the larger circle is tangent to the smaller. If the area of the annulus is A, express the length of the chord in terms of A. Share with your friends Share 4 Lovina Kansal answered this Dear student Let the radius of the smaller circle be rand radius of the larger circle be RGiven, area of annulus =Aand also we know that, A=πR2-πr2⇒A=πR2-r2⇒R2-r2=Aπ⇒R2-r2=Aπ ...(1)Now consider △OO'BBy pythagoras theoremOB2=OO'2+O'B2⇒R2=r2+O'B2⇒R2-r2=O'B2⇒R2-r2=O'BSo, AB=2O'B⇒AB=2×Aπ from (1) Regards 13 View Full Answer