15. 

    Area of larger triangle = 105 ft 2 equals 105 . ft squared

16. 

    Area of smaller hexagon = 23   m 2 equals . 23 , m squared

See Problem 3.

17. Remodeling The scale factor of the dimensions of two similar wood floors is 4 : 3. It costs $ 216 dollars 216  to refinish the smaller wood floor. At that rate, how much would it cost to refinish the larger wood floor?

18. Decorating An embroidered placemat costs $ 3 . 95 . dollars 3 . 95 .  An embroidered tablecloth is similar to the placemat, but four times as long and four times as wide. How much would you expect to pay for the tablecloth?

See Problem 4.

Find the scale factor and the ratio of perimeters for each pair of similar figures.

19. two regular octagons with areas 4   ft 2 4 , ft squared  and 16   ft 2 16 , ft squared
20. two triangles with areas 75   m 2 75 , m squared  and 12   m 2 12 , m squared
21. two trapezoids with areas 49   cm 2 49 , cm squared  and 9   cm 2 9 , cm squared
22. two parallelograms with areas 18   in . 2 18 in , . squared  and 32   in . 2 32 in , . squared
23. two equilateral triangles with areas 16 3 ft 2 16 square root of 3 . ft squared  and 3 ft 2 square root of 3 , ft squared
24. two circles with areas 2 π   cm 2 2 pi . , cm squared  and 200 π   cm 2 200 pi . , cm squared

B Apply

The scale factor of two similar polygons is given. Find the ratio of their perimeters and the ratio of their areas.

25. 3 : 1
26. 2 : 5
27. 2 3 2 thirds
28. 7 4 7 fourths
29. 6 : 1
30. The area of a regular decagon is 50   cm 2 . 50 , cm squared , .  What is the area of a regular decagon with sides four times the sides of the smaller decagon?
    1. 200   cm 2 200 , cm squared
    2. 500   cm 2 500 , cm squared
    3. 800   cm 2 800 , cm squared
    4. 2000   cm 2 2000 , , cm squared

31. Error Analysis A reporter used the graphic below to show that the number of houses with more than two televisions had doubled in the past few years. Explain why this graphic is misleading.

    

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