Chords AB and CD of a circle intersect externally at P. If AB = 7 cm, CD = 1 cm and PD = 5 cm, then the length of PB (in cm) is :
Answer & explanation
Correct answer: option 1
We have a concept,
PD × PC = PB × PA
5 × 6 = PB × (PB + 7)
30 = PB × (PB + 7)
By putting the value of PB = 3 we can satisfy the given equation.
so, the value of PB = 3 cm