Question

can anyone help me with this prblm ......que. no. 14

Answer 1

Hey!!!

Assume a common centre O is the two concentric circles.

Draw OL perpendicular to AD

=> OL bisects AD and BC(theorem).

=> AL = LD---------(1)
and
=> BL = LC---------(2)


Subtract (2) from (1).

=> AL - BL = LD - LC

=> AB = CD

HENCE PROVED

Hope this helps you

Answer 2

first join O(centre) to the chord.
now by the theorem "line through the centre bisects the chord" so OE bisects AD as well as BC ..(they are concentric circles)
then,
AE=ED...(1)
BE=EC....(2)
substracting (2) from (1)
AE-BE=ED-EC
AB=CD....hence proved!!n
bruh....!