Let P be a fixed point and T a given triangle that contains the point P. Translate the triangle T by a given vector v and denote by T′ this new triangle. Let r,R, respectively, be the radii of the smallest disks centered at P that contain the triangles T,T′, respectively. Prove that r+∣v∣≤3R and find an example to show that equality can occur. vectorgeometry unsolvedgeometry