To connect PO, we need to find the length of PO and extend it. By constructing secant, it can be solved by secant theorem. Solution: connect the intersection of PO in c and extend the intersection of PO in d;

PB = 8cm，AB= 10cm，

∴pa= 18cm；

From secant theorem we get: PB? PA=PC？ PD；

If the distance from point p to the center of the circle is xcm, then:

(x-9)(x+9)= 144，

The solution is x = 15cm.

Therefore, the distance from point P to the center of the circle is 15cm. ..