17+Proportions+Formed+by+Parallel+Lines

Definition 
If a line is parallel to one side of a triangle and intersects the other two sides in two distinct points, then it separates these sides into segments of proportional length. If a line intersects two sides of a triangle and separates the sides into corresponding segments of proportional lengths, then the line is parallel to the third side. A segment whose endpoints are the midpoints of two sides of a triangle is parallel to the third side of the triangle, and its length is half the length of the third side. If three or more parallel lines intersect two transversals, then they cut off the transversals proportionally. If three or more parallel lines cut off congruent segments on one transversal, then they cut off congruent segment on every transversal.

Rules, Proportions & Formulas
TRIANGLE PROPORTIONALITY THEOREM: If a line is parallel to one side of a triangle and intersects the other two sides in two distinct points, then it separates these sides into segments of proportional length.



If three or more parallel line intersect two trasversals, then they cut off the transversals proportionally.

Examples
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There must be 3 examples that cover 3 different aspects of the material in the section, not 3 similar problems. They must not be too simple – they should be of comparable difficulty to the problems we solved in class. The answers must be correct, and the problems and solutions must be typed and professional-looking.

Part 4: Web Links (6 pts total) There must be 3 different sites. The sites must be relevant, meaning they show how to do problems like the ones we did in class.