


Challenge 


Circle:
The set of all points in a plane that are the same distance, called the radius, from a given point, called the center. 
Optimizing Triangles Using Radii: Find the triangles with maximum and minimum area that contain two sides determined by radii of the circle.
Four Dogs: Explore the paths of four dogs, each of which starts at a different vertex of a square.
Equation of a Circle: Find the equation of a circle based on its radius, center, and locus of points.
Grazing for Mooey: How many square meters of grazing ground does Mooey the Cow have?


