Solve each problem. (Modeling) Archaeology An archaeology professor belie...

Solve each problem.

(Modeling) Archaeology An archaeology professor believes that an unearthed fragment is a piece of the edge of a circular ceremonial plate and uses a formula that will give the radius of the original plate using measurements from the fragment, shown in Figure A. Measurements are in inches.

In Figure B, a is the length of chord NP, and b is the distance from the midpoint of chord NP to the circle. According to the formula, the radius r of the circle, OR, is given by

What is the radius of the original plate from which the fragment came?