Algebra 1 Common Core Student Edition, Grade 8-9

G ot It? 2. A m an w ho is 6 ft tall is standing next to a flagpole. The shadow of th e

m an is 3.5 ft an d the shadow of th e flagpole is 17.5 ft. W hat is th e h eight of

the flagpole?

A scale d raw in g is a drawing th a t is sim ilar to a n actual object or place. Floor plans,

blueprints, an d m aps are all exam ples of scale drawings. In a scale drawing, the ratio of

any length on th e draw ing to th e actual length is always th e sam e. This ratio is called the

scale of the drawing.

In terpreting Scale D raw in g s

Maps What is the actual distance from Jacksonville to Orlando? Use the ruler to

measure the distance from Jacksonville to Orlando on the map below.

TM nk
What does the scale
of the map tell you?
The scale te lls you th a t
each inch on the map
represents 110 mi of
actual distance.

map distance

Relate map scale = —-—r actual distance------

1

110

1.25

x

Define Let x = the total distance from Jacksonville to Orlando.

Write

l(x) = 110(1.25) Cross Products Property

x = 137.5 Multiply.

The actual distance from Jacksonville to O rlando is 137.5 mi.

G ot It? 3. a. The distance from Jacksonville to Gainesville on th e m ap is ab o u t 0.6 in.

W hat is th e actual distance from Jacksonville to Gainesville?

b. Reasoning If you know th a t the actual distance betw een two cities is

250 mi and that the cities are 2 in. ap a rt on a m ap, how can you find the

scale of th e m ap?

A scale m odel is a th ree-d im en sio n al m odel th at is sim ilar to a three-dim ensional

object. The ratio of a linear m easu rem en t of a m odel to th e corresponding linear

m easu rem en t of the actual object is always th e sam e. This ratio is called th e scale of

the model.

ATLANTIC

OCEAN

132 Ch ap t er 2 So lvin g Eq u at io n s