mU = 122 mW = 119 x = 8

Section 8.3 Similar Polygons Chapter 8 Similarity Section 8.3 Similar Polygons

B  Q, A  P, C  R, D  S Definition Similar Polygons B  Q, A  P, C  R, D  S Trapezoid ABCD ~ Trapezoid PQRS

Corresponding components must line up in the similarity statement J  R K  S L  T

Corresponding components must line up in the similarity statement T  M U  N V  O

Corresponding components must line up in the similarity statement W  D X  E Y  F Z  G

No, Corresponding Angles must be congruent

L  T M  P N  O LMN ~ TPO Definition Similar Polygons

Definition: Scale Factor The ratio of any two corresponding sides of similar polygons. Same no matter what two sides are chosen Scale Factor

Scale Factor

Scale Factor 5 NO = 4

U  O mO + mN = 180 mO + 125 = 180 mO = 55 mU = 55

p = MN + NO + OL + LM p = 2.4 + 4 + 4 + 5 P = 12.8 4 2.4 4

The Perimeter Ratio is the same as the scale factor Theorem The Perimeter Ratio is the same as the scale factor Scale Factor = Perimeter Ratio

4x = 36 x = 9 4y = 48 y = 12

y = 16 Opposites sides of a parallelogram are congruent 16x = 216

Ratio of the perimeters = the ratio of the sides 5x = 144 The perimeter of ABC =

HW #12 Pg 476-479 8-38