Copy of Square and Circle

Can you determine the radius of the circle? You should not have to measure. What if the side of the square is ā€œsā€ rather than ā€œ8ā€?[br][br][b]Hint[/b]: To solve this kind of problem, it is usually useful to construct some extra lines and explore triangles and relationships that are created. If you know basic algebra, you might set up some equations based on the relationships in the figure.

Information: Copy of Square and Circle