Answer:
Given,
AB and CD are two chords
In ∆ PAC and ∆ PDB
∠???????????? = ∠????????????
∠???????????? = ∠????????????
By ???????? ???????????????????????????????????????? ???????????????????????????????????? ∆???????????? ~????????????
When two triangles are similar, then the ratios of lengths of their corresponding sides are proportional.
∴
PB = PC. PD