There are two concentric circles with centre O and radii 5 cm and 3 cm. PA and PB are tangents to the circle from an external point P. If PA = 12 cm, then the length PB(in cm) is :
1
10
2
\(4\sqrt{10}\)
3
12
4
\(\sqrt{178}\)
There are two concentric circles with centre O and radii 5 cm and 3 cm. PA and PB are tangents to the circle from an external point P. If PA = 12 cm, then the length PB(in cm) is :