Search
GeoGebra
  • Home
  • Resources
  • Profile
  • Classroom
  • App Downloads

Lesson 86. Properties of Parallel Lines

Author:Norm Prokup

T6-criterion for parallel lines

[bgcolor=orange] If two lines are intersected by a third line, and alternate interior (or exterior) angles are equal, then the original two lines are parallel. [/bgcolor]

New Resources

  • רישום חופשי
  • 立体几何-公理3及推论
  • seo tool
  • bewijs stelling van Pythagoras
  • Mosaic

Discover Resources

  • tikz problem
  • Quads
  • chord on unit circle angle at center
  • Qualitative Graph Corley
  • Split a 30cm wire
  • ModuL10B.2_KASIATI_SMP ISLAM MA'ARIF 02 KOTA MALANG

Discover Topics

  • Matrices
  • Pythagoras or Pythagorean Theorem
  • Congruence
  • Natural Numbers
  • Expected Value
AboutPartnersHelp Center
Terms of ServicePrivacyLicense
Graphing CalculatorCalculator SuiteMath Resources

Download our apps here:

Download_on_the_App_Store_Badge_US-UK_RGB_blk_4SVG_092917

© 2025 GeoGebra®