130 likes | 225 Views
Learn about the concept of proportionality in different contexts to find missing side measurements of similar polygons. Explore new vocabulary related to polygons, scale factor, and corresponding parts.
E N D
Chapter 4 4.7: Similar Polygons
What you’ll learn…and why? What? The concept of proportionality to measurement in different contexts. Why? To be able to find the measurement of missing sides of similar polygons.
New Vocabulary POLYGON SIMILAR CORRESPONDING PARTSCONGRUENTSCALE FACTOR
POLYGONS • A POLYGON consists of a closed figure made of three or more line segments. Two polygons that have the same shape are called SIMILAR polygons.
CORRESPONDING PARTS The parts of similar figures that MATCH are called CORRESPONDING PARTS. X A B Y W C D Z
If two polygons are similar, then • Their corresponding angles are CONGRUENT, or have the same measure, and • The measures of their corresponding sides are proportional X A B C Y Z
Example Determine whether rectangle HJKL is similar to rectangle MNPQ. Explain. M N 10 H J 7 6 3 L K Q P
Scale Factor The ratio of the lengths of two corresponding sides of two similar polygons is called the SCALE FACTOR. You can use the scale factor of similar figures or a proportion to find missing measures.
The ratio of the perimeter of similar polygons = the scale factor
HOMEWORK #5 Worksheet 4.7