This video covers the Triangle Proportionality Theorem and the Converse to the Triangle Proportionality Theorem. Essentially, if you have a triangle that has two sides being intersected by a line and that line is parallel to the third side of the triangle, the intersecting parallel lines cuts the two sides being intersected proportionally. I go through this lesson and solve several practice problems as well.
Lesson 8.4 (Part 2) - Notes and Practice
Three Parallel Lines and Triangle Bisector Theorems
This videos explains the Three Parallel Lines and Triangle Bisector Theorems. I explain that if you have 2 lines being intersected by 3 or more parallel lines, the 2 lines are cut up proportionally. I also explain that if you have a triangle with an angle bisector, it will cut the triangle proportionally as well. I solve several examples going over both concepts.
