1. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.

2. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.
Required Geometry:
The perpendicular bisector of a chord of a circle will pass through the center of the circle.
The midpoint of a line segment connecting the points (a,b) and (c,d) is the point ((a+c)/2, (b+d)/2).
That is, find the average of x coordinates and the average of the y coordinates.

3. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.
Find two of the three lines determined by pairs of points.

4. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.
Find the points on each line halfway between the original points (i.e. midpoints).

5. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.
Find the lines perpendicular to each line at the midpoint.

6. Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the center of the circle.
Find the point of intersection of the perpendiculars (this is the center of the circle).

7. Radius = 5 Given three points of a circle: (-1,1), (7,-3), (-2,-6).
Find the circle.
Determine the equation of the circle.
Radius = 5