Answer:
PA = 8 cm
Explanation:
First, create a right triangle with legs OA and SA and hypotenuse OS. Use the Pythagorean Theorem to get the length of OS. Since this is a pythagorean triple (3-4-5) triangle, the hypotenuse is 5, meaning that OS is 5 cm long. Because OS and OP are both radii of the circle, they are equal. So, OP = 5 cm. Finally, simply add OA and OP to get PA:
OA + OP = PA
3 + 5 = PA
PA = 8 cm