Angles made by parallel lines Parallel lines are straight lines which have the same direction and so never meet. Arrowheads show lines are parallel.

Learn how to apply formulae for the interior and exterior angles of a polygon and how to create tiling patterns and tessellations with this GCSE guide.

The Art Angle The Art Angle Podcast: Why Art Biennial Superstars Exist in a Parallel Universe [Re-Air] Writers Ben Davis and Kate Brown discuss our Biennial Art Project.

Elon Musk talks proof-of-concept tunnel parallel to the 405 in Los Angeles Musk's youngest company will keep LA Metro informed of its plans.