7.5

Today in class we learned about proportional perimeters and similar triangles. We learned the Proportional Perimeters Theorem which states that if two polygons are similar then then the ratio of the perimeters is equal to the ratio of their corresponding sides. Here are the Dyknows we received in class and some examples. And also, here is the Arrow Theorem and an example.

Section 7.3: Similar Triangles

Angle-Angle Theorem (AA Thm)- If 2 angles of 1 triangle are congruent to 2 angles of another triangle, then the 2 triangles are similar.

Side-Side-Side Theorem (SSS Similarity Thm)- If the lengths of the corresponding sides of 2 triangles are proportional, then the triangles are similar.

Side-Angle- Side Theorem (SAS Similarity Thm)- If an angle is congruent to another angle in a second triangle, and the length of the two sides that make up the angle are proprtional, then the 2 triangles are similar.

Similarity of Triangles

-Reflexive
-Symmetric
-Transitive

Trial

This is a posting trial!!

Section 7.2

Similar Polygons:

In order for two polygons to be similar to each other they must be one of two things:
1. Corresponding angles are congruent
2. lengths of corresponding sides are proportional

Proper Notation: When writing that two shapes are parallel always use ~

An example of two simular polygons is like the one below

These polygons are simular because their angles as shown correspond to each other. The diagram below shows that their corresponding sides are porpotional.












Another example of similar polygons is at right: the two polygons are proven similar because the ratios of corresponding sides are congruent








Vocab Review: Below are some vocabulary terms that would be helpful to know.