Answer:
6.8 inches
Explanation:
The shortest distance from P to the circle is along the line between P and the center of the circle. That line is the hypotenuse of the right triangle whose legs are PQ and QC (where C is the circle center).
The Pythagorean theorem tells you
... PC² = PQ² +QC²
... PC² = 13² +9² = 250
... PC = √250 = 5√10 ≈ 15.8114 . . . . inches
The distance from P to the circle is 9 in less than this, so is
... 15.8114 - 9 = 6.8114 ≈ 6.8 . . . . inches
