Page 701 - Basic College Mathematics with Early Integers

678 C HAPTE R 9 I GEOMETRY

Given that the pairs of triangles are similar, find the length of the side labeled n. Round your results to 1 decimal place.

47. 48.
n 58.7
11.6 20.8
n 12.6
5.2 7.8

49. In your own words, describe any differences in 50. Describe a situation where similar triangles would
similar triangles and congruent triangles. be useful for a contractor building a house.

51. A triangular park is planned and waiting to be 52. John and Robyn Costello draw a triangular deck on
approved by the city zoning commission.A drawing their house plans. Robyn measures sides of the deck
1 1
of the park shows sides of length 5 inches, 7 inches , drawing on the plans to be 3 inches, 4 inches, and
5 2 2
1
and 10 inches. If the scale on the drawing is 6 inches. If the scale on the drawing is in. = 1 foot,
1 8 4
in. = 10 ft , find the actual proposed dimensions
4 find the lengths of the sides of the deck they want
of the park. built.

Chapter 9 Group Activity

The Cost of Road Signs Sections 9.1, 9.2, 9.4
There are nearly 4 million miles of streets and roads in Road Sign Costs
the United States. With streets, roads, and highways Type of Sign Cost
comes the need for traffic control, guidance, warning, and
Regulatory, warning, marker $15–$18 per square foot
regulation. Road signs perform many of these tasks. Just
in our routine travels, we see a wide variety of road signs Large guide $20–$25 per square foot
every day.Think how many road signs must exist on the 4
million miles of roads in the United States. Have you Type of Post Cost
ever wondered how much signs like these cost?
U-channel $125–$200 each
The cost of a road sign generally depends on the
type of sign. Costs for several types of signs and sign Square tube $10–$15 per foot
posts are listed in the table. Examples of various types of Steel breakaway posts $15–$25 per foot
signs are shown below.
Regulatory Warning Marker Large Guide Posts
The cost of a sign is based on its area. For diamond,
square, or rectangular signs, the area is found by multi-
STOP
plying the length (in feet) times the width (in feet).Then
the area is multiplied by the cost per square foot. For
signs with irregular shapes, costs are generally figured as
U-channel
if the sign were a rectangle, multiplying the height and
width at the tallest and widest parts of the sign.

Group Activity
Locate four different kinds of road signs on or near your
Square tube campus. Measure the dimensions of each sign, including
the height of the post on which it is mounted. Using the
cost data given in the table, find the minimum and maxi- Copyright 2012 Pearson Education, Inc.
mum costs of each sign, including its post. Summarize
your results in a table, and include a sketch of each sign.
Steel breakaway posts