10.4 Perimeters and Areas of Similar Figures...10.4_Perimeters_and_Areas_of_Similar_Figures 1 April...
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10.4_Perimeters_and_Areas_of_Similar_Figures 1 April 14, 2010 Apr 137:51 AM 10.4 Perimeters and Areas of Similar Figures Objective: Find the perimeters and areas of similar figures.
Transcript of 10.4 Perimeters and Areas of Similar Figures...10.4_Perimeters_and_Areas_of_Similar_Figures 1 April...
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10.4 Perimeters and Areas of Similar Figures
Objective: Find the perimeters and areas of similar figures.
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Example #1: The trapezoids at the right are similar.
The ratio of the lengths of corresponding sides is or .
A. Find the ratio (smaller to larger) of the perimeters.
B. Find the ratio (smaller to larger) of the areas.
69
23
23
23( )
2
=49
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Example #2: Two similar polygons have corresponding sides in the ratio 5 : 7.
A. Find the ratio of their perimeters.
B. Find the ratio of their areas.
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27.5 x
425 =
( )252= 425
Example #3: The area of the smaller regular pentagon is about 27.5 cm2. What is the area of the larger regular pentagon?
Finding Areas Using Similar Figures
410 = 2
5
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Example #4: The corresponding sides of two similar parallelograms are in the ratio 3 : 4. The area of the larger parallelogram is 96 in.2. Find the area of the smaller parallelogram.
Finding Areas Using Similar Figures
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Example #5: The similarity ratio of the dimensions of two similar pieces of window glass is 3 : 5. The smaller piece costs $2.50. What should be the cost of the larger piece?
Finding Areas Using Similar Figures
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Example #6: The areas of two similar triangles are 50 cm2 and 98 cm2. What is the similarity ratio? What is the ratio of the perimeters?
Finding Similarity and Perimeter Ratios
5 : 7
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Example #7: The areas of two similar rectangles are 1875 ft2 and 135 ft2. Find the ratio of their perimeters.
Finding Similarity and Perimeter Ratios
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Homework: page 555 (1 - 16)
