A Line Crossing Two Parallel Lines Makes Alternate Angles Equal

Let the line intersect the parallel lines and at and . Then the alternate angles at and are equal. To see this, rotate half of the figure by 180° around the midpoint of to make the alternate angles coincide.

SNAPSHOTS

  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.







Related Curriculum Standards

US Common Core State Standards, Mathematics