Lesson 86. Properties of Parallel Lines

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]

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Parallelogram Anatomy
Superellipse
bewijs stelling van Pythagoras
Building Figures with Set Areas
Regular Polygons and Equivalent Triangles

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Restricting Domains
GeoGebra Probability and Statistics Quickstart Info
The sine curve
Trapézio MN,MP,MQ,NP,NQ e PQ
Geometric Proof of Double Angle Sine Identity

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Isosceles Triangles
Complex Numbers
Right Triangles
Trapezoid
Centroid or Barycenter