This figure shows circle O with chords AC and BD.
m arc AB=36 degrees; m arc CD=36 degrees; AP=6m; PC=8m
What is BD?
Draw AD, BC
In triangle APD, angle ADP = 18° and angle DAP = 18°......so......AP = PD = 6m
Similarly, in triangle BPC, angle PBC = 18° and angle PCB = 18° ...so.... PC = BP = 8m
BD = BP + PD = 8 + 6 = 14 m