1. SIMILAR POLYGONS Lesson 3 – 2 MATH III

2. 1:18 Model Original car

3. Similar polygons ( ~ ) Polygons with the same shape Corresponding angles are congruent Correpsonding sides are proportional For example, if ∆XYZ ~ ∆MOP…  X =  M  Y =  O  Z =  P ANDAND

4. Another example, if Pentagon ABCDE ~ Pentagon MOPQR…  A =  M  B =  O  C =  P  D =  Q  E =  R 1/3 is the SCALE FACTOR, the ratio of the lengths of two corresponding sides of two similar polygons. 2 6

5. A convenient way to name corresponding vertices is to use A and A’, B and B’, and so on. Quad ABCD ~ Quad A’B’C’D’ 1.Find the scale factor 2.Find x, y, z 3.Find the perimeter of each quadrilateral. What is the ratio of the perimeters? How does this compare to the scale factor? 15 12 x 18 y 16 z 20

6. Find the scale factor in each figure, then solve for the variables, yo.

7. Assume the two triangles are similar - find x and y.