You can move the points around. The segments on the right will always maintain that AB = DE and side across from the right angles will always be equal to maintain HL congruence between the triangles. [br][br]Try to make a triangle.[br][br]If the triangle you make is green, then the triangles are congruent. If it is red then they are not.[br][br]Can you find a pair of non-congruent triangles?
What type of triangles are both figures?
What else do you know about this type of triangle?[br]Why do you think the HL congruency theorem works for this type of triangle?