Parallel Lines


lines, on the same plane, are parallel if they never meet and always remain the same distance apart.

a line crossing parallel lines is called a transversal.

three special types of angles involve parallel lines and a transversal:

  • corresponding angles
  • alternate angles
  • co-interior angles

Key Skills

solve angle problems involving corresponding angles, alternate angles and co-interior angles.


parallelcorresponding anglesalternate angles, co-interior angles,transversalsupplementary anglescomplementary angles, symmetry