
 
compute the center of the circle passing through the points $$p, $$q, and $$r. Precondition: $$p, $$q, and $$r are not collinear.  

 
compute the center of the circle passing through the vertices of $$t. Precondition: $$t is not degenerate.  

 
compute the center of the circle passing through the points $$p, $$q, and $$r. Precondition: $$p, $$q, and $$r are not collinear.  

 
compute the center of the circle passing through the vertices of $$t. Precondition: $$t is not degenerate.  

 
compute the center of the sphere passing through the points $$p, $$q, $$r, and $$s. Precondition: $$p, $$q, $$r, and $$s are not coplanar.  

 
compute the center of the sphere passing through the vertices of $$t. Precondition: $$t is not degenerate. 