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Ch 9.7. Learning Target: I will be able to identify and use proportional relationships of similar triangles. Standard 11.0 Students determine how changes in dimensions affect the perimeter of common geometric figures. Ch 9.7 Perimeters and Similarity. Ch 9.7. Concept. Ch 9.7.
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Ch 9.7 Learning Target: I will be able to identify and use proportional relationships of similar triangles. Standard 11.0 Students determine how changes in dimensions affect the perimeter of common geometric figures. Ch 9.7Perimeters and Similarity
Ch 9.7 Concept
Ch 9.7 Use a Scale Factor to Find Perimeter If ABCDE ~ RSTUV, find the scale factor of ABCDE to RSTUV and the perimeter of each polygon. Example 4
Ch 9.7 The scale factor ABCDE to RSTUV is or . Write a proportion to find the length of DC. 4 __ AE ___ 7 VU Since DC AB and AE DE, the perimeter of ABCDE is 6 + 6 + 6 + 4 + 4 or 26. Use a Scale Factor to Find Perimeter Write a proportion. 4(10.5) = 7 ● DC Cross Products Property 6 = DC Divide each side by 7. Example 4
Ch 9.7 Use a Scale Factor to Find Perimeter Use the perimeter of ABCDE and scale factor to write a proportion. Let x represent the perimeter of RSTUV. Theorem 7.1 Substitution 4x = (26)(7) Cross Products Property x = 45.5 Solve. Answer:The perimeter of ABCDE is 26 and the perimeter of RSTUV is 45.5. Example 4
Ch 9.7 If LMNOP ~ VWXYZ, find the perimeter of each polygon. A.LMNOP = 40, VWXYZ = 30 B.LMNOP = 32, VWXYZ = 24 C.LMNOP = 45, VWXYZ = 40 D.LMNOP = 60, VWXYZ = 45 Example 4