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Similar Polygons. Section 4-5. A. I. H. J. K. L. B. C. A simple, closed figure formed by three or more line segments is called a polygon. B. C. X. Y. W. Z. A. D. Polygon ABCD ~ Polygon WXYZ. Polygons that have the same shape are called similar polygons. B. C. X. Y. W. Z.
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Similar Polygons Section 4-5
A I H J K L B C A simple, closed figure formed by three or more line segments is called a polygon.
B C X Y W Z A D Polygon ABCD ~ Polygon WXYZ Polygons that have the same shape are called similar polygons.
B C X Y W Z A D Corresponding Angles <A -- <W <B -- <X <C -- <Y <D -- <Z Corresponding Sides AB – WX BC – XY CD – YZ DA -- ZW The parts of similar figures that “match” are called corresponding parts.
A L ABC ~ LMN C B N M • If two polygons are similar, then: • Their corresponding angles are congruent, or have the same measure • Their corresponding sides are proportional.
A L 7 7 14 14 C B N M 5 10 AC 7 = LN 14 AB 7 = LM 14 BC 5 = MN 10 • How to identify if polygons are similar: • Check to see if corresponding angles and sides are congruent (Use a proportion).
A B E F 6 3 G C H D The scale factor from square ABCD to square EFGH is 6/3 or 2. The scale factor from square EFGH to square ABCD is 3/6 or ½. The ratio of lengths of two corresponding sides of two similar polygons is called the scale factor.
A B E F 15 10 m 12 G C H D The scale factor from square ABCD to square EFGH is FG/BC 10/15 or 2/3. 12 2 = M 3 12(3) = m(2) 36 = 2m 18 = m • How to find missing measures of similar polygons: • Create a proportion and cross multiply.