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]

New Resources

繪畫垂直線
Isosceles Right Triangle
Function Art 3D - Flower
Perpendicular Lines: Quick Exploration
Midpoint Theorem Questions: Mild

Discover Resources

Toupie
tennis person geometry project
Implicit Locus demo
Geoboard Area 5A
Notes p.1 Example 1

Discover Topics

Equilateral Triangles
Random Experiments
Statistical Characteristics
Difference and Slope
Conic Sections