Circles can be found along the Gambia
River in western Africa. The stones
are believed to be over 1000 years old.
In one of the circles at Ker Batch,
three stones have approximate
coordinates of A(3, 1), B(4, -2),
and C-6, -2).
a. What are the coordinates of the
center of the stone circle?
b. Each unit of the coordinate
plane represents 1 ft. What is the
diameter of the stone circle?