Two equal chords AB and CD of a circle when produced intersect at a point P. Prove that PB = PD
Given: Two equal chords AB and CD of a circle intersect at a point P.
To Prove: PB = PD
Proof: Given,
Join OP draw OL AB and OM
CD
AB = CD
OL = OM (equal chords are equidistant from the centre)
Consider OLP and
OMP
OL = OM
OLP =
OMP (both are 90o)
OP = OP
OLP
OMP (SAS congruence)
LP = MP …(i) (CPCT)
AB = CD (Given)
BL = DM …(ii)
Subtracting equation (ii) from equation (i) we get
LP – BL = MP – DM
PB = PD
Hence proved.