Answer is 8.35 cm radius.
Step by step. The circle is inscribed in a square with a perimeter of 66.8 cm.
First find the length of one side of the square. All four sides will be the same, so divide 66.8 by 4 = 16.7 cm.
Now, we know the diameter of the circle is the same as the length of the square, 16.7 cm. We also know the radius is 1/2 diameter, so 16.7 divided by 2 = 8.35 cm radius.
Problem solved.
