ANGLES IN PARALLEL LINES Corresponding Angles • Have the SAME amplitude (same size) • BOTH belong to the SAME SIDE of the transversal line • One of them in between the parallel lines and the other one outside the parallel lines. Alternate Angles • Have the same amplitude (same size) • Belong to DIFFERENT SIDE of the transversal line • BOTH of them in between the parallel lines OR BOTH outside the parallel lines. VERTICAL ANGLES • Have the same amplitude (same size) • Share the vertex • Are on DIFFERENT SIDES with respect to the vertex.