Given: △abc≅△def, △klm≅△def prove: △abc≅△klm set up as a two-column proof. there are three triangles they are equal to each other. triangle 1: ∠a, ∠b, ∠c triangle 2: ∠d, ∠e, ∠f triangle 3: ∠k, ∠l, ∠m