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Geometry 6.3 Big Idea: Use Similar Polygons. Similar Polygons : Two polygons where corresponding angles are congruent and corresponding side lengths are proportional (not congruent) Symbol for similarity is ~.
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Geometry 6.3 Big Idea: Use Similar Polygons
Similar Polygons: Two polygons where corresponding angles are congruent and corresponding side lengths are proportional (not congruent) Symbol for similarity is~
Scale Factor: In two similar polygons, the ratioof the lengths of two corresponding sides. All corresponding sides have the same ratio for similar polygons.
Theorem 6.1 Perimeters of Similar Polygons If two polygons are similar, then the ratio of their perimeters is equal to the ratios of their corresponding sides (scale factor).
Example: In the diagram, List all pairs of congruent angles. Check that the ratios of corresponding sides lengths are equal. Write ratios of the corresponding side lengths in a statement of proportionality. What is the scale factor? What is the ratio of the perimeters?
Are these triangles similar? • If yes, what is the scale factor? • What is the ratio of the perimeters?
Example: In the diagram, Find the value of x.
In the diagram, Find the value of x. What is the scale factor of QRST to ABCD?