Question

If a line intersect two concentric circles (circles with the same centre) with centre o at a b c and d prove that ac=bd

Answer 1

we know that perpendicular from the center bisect the chord so,

BE=EC ...........1

similarly,

AE=ED ...........2

Subtract equation 1 from equation 2,

AE-BE=ED-EC

AB=CD

Hence,proved

Hope it helps you....