1 / 11

9-2 Similar Polygons

9-2 Similar Polygons. Geometry September 12, 2013. OBJECTICE. Students will learn to identify similar polygons. Identifying Similar Polygons. Definition: Similar Polygons

lihua
Download Presentation

9-2 Similar Polygons

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 9-2Similar Polygons Geometry September 12, 2013

  2. OBJECTICE Students will learn to identify similar polygons

  3. Identifying Similar Polygons Definition: Similar Polygons • Two polygons are similar if and only if their corresponding angles are congruent and the lengths of their corresponding sides are proportional.

  4. Similar polygons • If ABCD ~ EFGH, then G H C D F B A E

  5. Similar polygons • Given ABCD ~ EFGH, solve for x. G H C D 6 x B F 2 4 A E 2x = 24 x = 12

  6. Is ABC ~ DEF? Explain. B D 6 E 13 12 5 7 A C F 10 ABC is not similar to DEF since corresponding sides are not proportional. ? ? yes no

  7. Similar polygons Given ABCD ~ EFGH, solve for the variables. G H C D 5 x B F 10 2 y 6 A E

  8. Quadrilateral JKLM is similar to PQRS. Find the value of z. R K L S 15 Q z + 2 6 P J M 10 15z + 30= 60 15z = 30 z = 2

  9. If two polygons are similar, then the ratio of the lengths of two corresponding sides is called the scale factor. Ex: Scale factor of this triangle is 1:2 9 4.5 3 6

  10. Theorem • If two polygons are similar, then the ratio of their perimeters is equal to the ratios of their corresponding side lengths. • If KLMN ~ PQRS, then

  11. Given ABC ~ DEF, find the scale factor of ABC to DEF and find the perimeter of each polygon. E P = 8 + 12 + 20 = 40 B P = 4 + 6 + 10 = 20 12 20 10 6 A C D F 8 4 CORRESPONDING SIDES 4 : 8 1 : 2

More Related