Answer: 10 inches.
Step-by-step explanation:
Since the pecan pie is a circle, you can use this formula:
Where "r" is the radius and is the central angle of the arc in radians.
If the pecan pie has been cut into 8 equal pieces then the central angle is:
Now you know the arc length and the central angle, then, you can solve for "r" from :
Substituting values, you get that the radius of the pecan pie rounded to the nearest whole number is: