In figure, PA and PB are tangents to the circle from an external point P. CD is another tangent touching the circle at Q. If PA = 12 cm, QC = QD = 3 cm, then find PC + PD.
PA=PB=12 cm (length of tangent)
Similarly,
QC=AC=3 cm
QD=BD=3cm
PC=PA-AC=12-3=9cm
Similarly
PD=PB-BD=12-3=9cm
Hence,
PC+PD=9+9=18cm