[list=1][*][color=#980000]Assume your statement to be false.[br][/color][/*][*][color=#980000]Proceed as you would with a direct proof.[br][/color][/*][*][color=#980000]Come across a contradiction.[br][/color][/*][*][color=#980000]State that because of the contradiction, it can't be the case that the statement is false, so it must be true.[/color][br][/*][/list]

[color=#980000]If we can not create a differnt triangle, than we know that the information given is enough to create congruent triangles[br][br] If we are able to create a different triangle than we know that we can not create congruent triangles with that information.[/color]