Question

In the given figure, AP = 4 cm, OA = 3 cm, OB = 2 cm, find PB​

Answer 1

Answer:

PB = $\sqrt{21}$ or PB = 4.582

Step-by-step explanation:

Two concentric circles with center O. OA is 3 cm and OB is 2 cm.  

Join OP.

Now, in ΔOAP

∠OAP=90°   (Angles between radius and tangent)

OA²  + AP²  = OP²

3² + 4² = OP²

OP = 5 cm

In ΔOBP,

OB²+ PB² = OP²

2² + PB² = 5²

PB² = 5² - 2²

PB = $\sqrt{21}$

PB = 4.582