SIMILAR POLYGONS Lesson 3 – 2 MATH III
1:18 Model Original car
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
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
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? x 18 y 16 z 20
Find the scale factor in each figure, then solve for the variables, yo.
Assume the two triangles are similar - find x and y.