This is the concept of translation; Given that triangle A (-1,3), B(-1,1), C(3,1) has been translated to A'(2,-1), B'(2,-4), C(6,-4) the from the diagram we see that the coordinates of the triangle ABC have been moved by 3 units to the right while the y coordinates have been moved by 5 units down to form A',B',C'. We therefore conclude that the correct statement is: Triangle ABC has been translated 3 units to the right and 5 units down.