Download Geom 7.2 Guided Notes

NAME _____________________________________________ DATE ____________________________ PERIOD _____________
7-2 Guided Notes
Similar Polygons
Identify Similar Polygons Similar polygons have the same shape but not necessarily the same size.
Example 1: If △ABC ∼ △XYZ, list all pairs of congruent angles and write a proportion that relates the
corresponding sides.
Use the similarity statement.
Congruent angles:
Proportion:
Example 2: Determine whether the pair of figures is similar. If so, write the similarity statement and scale factor.
Explain your reasoning.
Step 1 Compare corresponding angles.
Step 2 Compare corresponding sides.
Scale Factor =
Exercises
List all pairs of congruent angles, and write a proportion that
relates the corresponding sides for each pair of similar
polygons.
1. △DEF ∼ △GHJ
2. PQRS ∼ TUWX
Determine whether each pair of figures is similar. If so, write the similarity statement and scale factor.
If not, explain your reasoning.
3.
Chapter 7
4.
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Glencoe Geometry
NAME _____________________________________________ DATE ____________________________ PERIOD _____________
7-2 Guided Notes (continued)
Similar Polygons
Use Similar Figures You can use scale factors and proportions to find missing side lengths in similar polygons.
Example 2: If △DEF ∼ △GHJ, find the scale factor of
Example 1: The two polygons are similar. Find x and y.
△DEF to △GHJ and the perimeter of each triangle.
Exercises
Each pair of polygons is similar. Find the value of x.
1.
2.
3.
4.
5. If ABCD ∼ PQRS, find the scale factor of ABCD
to PQRS and the perimeter of each polygon.
Chapter 7
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Glencoe Geometry