Presentation is loading. Please wait.

Presentation is loading. Please wait.

Two polygons are similar if and only if their corresponding angles are congruent and the measures of their corresponding sides are proportional. AB C.

Similar presentations


Presentation on theme: "Two polygons are similar if and only if their corresponding angles are congruent and the measures of their corresponding sides are proportional. AB C."— Presentation transcript:

1

2 Two polygons are similar if and only if their corresponding angles are congruent and the measures of their corresponding sides are proportional. AB C DE F Similar Polygons

3 Naming Similar Polygons When naming similar polygons, the vertices (angles, sides) must be named in the corresponding order. AB CD PQ R S

4 The scale factor is the ratio between a pair of corresponding sides. Scale Factor 10 24 30 8 or

5 Scale factor is the same as the ratio of the sides. Always put the first polygon mentioned in the numerator. Example: What is the scale factor from  ZYX to  ABC? The scale factor from  ABC to  ZYX is 2/1. If  ABC ~  ZYX, find the scale factor from  ABC to  ZYX. 7 9 5 18 10 14 C A B Z Y X ½

6 Example: The two polygons are similar. Solve for x, y and z. Step 3: Find the scale factor between the two polygons. Note: The scale factor has the larger quadrilateral in the numerator and the smaller quadrilateral in the denominator. Step1: Write the proportion of the sides. Step 2: Replace the proportion with values. Step 4: Write separate proportions for each missing side and solve. 5 z x 10 y 15 30 20 B C A D F G E H

7 B C A E F D If two triangles are similar, then the perimeters are proportional to the measures of the corresponding sides.

8 A B C D E F The perimeter of ΔABC is 15 + 20 + 25 = 60. Side DF corresponds to side AC, so we can set up a proportion as: Given: ΔABC ~ ΔDEF, AB = 15, AC = 20, BC = 25, and DF = 4. Find the perimeter of ΔDEF. Example: 15 20 25 4


Download ppt "Two polygons are similar if and only if their corresponding angles are congruent and the measures of their corresponding sides are proportional. AB C."

Similar presentations


Ads by Google