Lesson 4.1.2 Scale Drawings - PowerPoint Presentation

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Lesson 4.1.2 Scale Drawings

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Section 1:

What is a scale drawing?

Section 2: Using proportions to find unknown quantities involving scale drawings. Section 3: Reproducing a figure using a scale.Section 4: Finding area and perimeter of shapes involving scale.

Today…

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What is a scale drawing?

A Scale Drawing… is an ENLARGED or REDUCED drawing of an actual object.

Blueprints

Maps

Scale Models

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Blueprints

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2 inches : 4 feet

How would you like to live on the BEACH?

This blueprint has a scale of 2 inches : 4 feet 2 inches is the drawing length. 4 feet is the actual length.If something measures 2 inches on the blueprint, then in real life the measurement would actually be 4 feet.

Blueprints

of a house

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Maps

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Scale 2 inches = 25 miles

This map is a scale drawing because it is a reduced drawing of the state of Mississippi. 2 inches is the map/drawing length. 25 miles is the actual length.If you measure 2 inches on the map, it would actually be 25 miles in real life.

Maps

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Scale Models

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Independence Day

Scale ModelsScale 1:12

Did anyone see the movie “

Independence Day

” starring Will Smith? It is one of my favorite movies.

So… do you really think they blew up the actual white house? No way!

A scale model was built, and it was used in the movie to shoot that scene.

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Section 1:

What is a scale drawing?

Section 2: Using proportions to find unknown quantities involving scale. Section 3: Reproducing a figure using a scale.Section 4: Finding area and perimeter of shapes involving scale.

Moving on…

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You can use

proportions

to solve problems dealing with scales drawings.

Today, when setting up your proportions

keep this in mind…

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What is a Scale Drawing?

Using

proportions to find unknown Quantities involving scales drawings When setting up a proportion, you always want to put the “like things” across from each other.For example, look at this proportion:

Notice

…

The

are across from the

and

the

are across from the

.

 

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Example:

The scale of a map is 2 inches = 25 miles. Find the actual distance if the map distance is 3 inches.

 

 

Step 1:

Take the

scale

and make that the 1

st

ratio.

Step 2:

Take the other information

provided and make that your 2

nd

ratio.

Step 3:

Cross Multiply

Step 4:

Solve the equation.

=

 

You are given the 3 inches. It goes on the top because the “like things” go across from each other.

That means our unknown (

) goes on the bottom.

 

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On an architect’s drawing of a house,

1 inch represents1.5 feet. If the actual

bedroom window is 3 feet, how

many inches will it be on the drawing?

Guided Practice

Scale: 1 in = 1.5 ft

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You Try!

The scale on a map shows that

5 centimeters = 2 kilometers.Part A:What number of centimeters on the map represents an actual distance of 5 kilometers?

Part B:

What is the actual number

of kilometers that is represented by

2 centimeters on the map?

=

 

 

25

2x =

X =

12.5 cm

=

 

 

4

5x =

X =

0.8 km

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Section 1:

What is a scale drawing?

Section 2: Using proportions to find unknown quantities involving scale. Section 3: Reproducing a figure using a scale.Section 4: Finding area and perimeter of shapes involving scale.

Moving on…

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Reproducing a figure using a scale

We’ll move straight to an example problem…

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Example:

An architect made this drawing to represent a swimming pool. If the scale is 1 inch = 3 feet, what are the dimensions of the actual swimming pool?

To find the actual dimensions of the pool, set up and solve a proportion using the scale for each side.

 

 

 

 

Answer:

The dimensions of the actual swimming pool are

12 ft

by

15 ft

Swimming Pool

5 in.

4 in.

 

 

P= 12+12+15+15

P= 2(12+15)

P= 54 ft.

A=12x15

A= 180 ft.²

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Section 1:

What is a scale drawing?

Section 2: Using proportions to find unknown quantities involving scale. Section 3: Reproducing a figure using a scale.Section 4: Finding area and perimeter of shapes

involving scale.

Last section…

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An architect made this drawing to represent a swimming pool.

If the scale is 1 inch = 3 feet, what is the

perimeter and area of the actual swimming pool?

Swimming Pool

7 in.

5 in.

Guided Practice

 

 

 

 

Answer:

The dimensions of the actual swimming pool are

15 ft

by

21 ft

 

 

P= 15+15+21+21

P= 2(15+21)

P= 72 ft.

A= 15x21

A= 315 ft.²

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You Try

Julie is constructing a scale model of her room. The rectangular room is 10.5 inches by 8 inches.

If 1 inch represents 2 feet of the actual room, what is the perimeter and area of Julie’s room?

10.5 in.

8 in.

 

 

 

 

 

 

P= 16+16+21+21

P= 2(16+21)

P= 74 ft.

A= 16x21

A= 336 ft.²

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Sales tax and tips can also be computed using a proportion…………

1. Jess wanted to buy a new

guitar that cost $529.95.He had to pay Mississippi sales tax which is 7%.What will the total cost for the guitar?2. Cody took his family out to

eat. The total bill was $62.48. He decided to give his server a 20% tip, which

is also called the gratuity.

How much did he pay the server?

=

 

 

=

 

100T

 

 

= T

 

= Tax

 

=

 

 

=

 

100T

 

 

= Tip

 

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Closure

A

scale drawing is a reduced (or enlarged) drawing of an actual object.What is a example of a scale drawing?How do you solve problems that involve scales?The first ratio is always your ________?The second ratio is set up from the _______? When setting up ANY proportion, what is VERY IMPORTANT to remember?

Blueprints

,

Maps

,

Scale Models

Set up a Proportion

Scale

The other # in the problem.

Put “like things” across from each other!

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Time for Classwork!

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End of PowerPoint

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Scale Drawings

Let me explain using real life…

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Mississippi State university!

Home of the Bulldogs!

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Mississippi state is famous for…

Cowbells of course!

And Football!

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Mississippi state is famous for…

And, having great dairy

products such as cheese! MSU is an agricultural school for those thatdidn’t know.

#1 Vet School in the Country!

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Mississippi State University is also

famous for their

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School of Architecture

Architects design buildings and help in the construction of buildings!

Giles Hall

As most students are driving around campus late at night with their radios turned up as loud as possible having fun, architect students are working in Giles Hall designing buildings! Not an easy major, but very rewarding to see the finished product!

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Scale drawings

Architects use scale drawings everyday in their line of work.

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Famous architect

Minoru Yamasaki

Does anyone know this famous architect? What famous building or buildings did he build?

Look… he made the cover of Time Magazine!

Let me give you some hints.

Do not

holler out the answer!

Scale Models

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American Airlines

New York City

The famous building or buildings he designed have ties to American Airlines and New York City. Don’t say the answer. If you still don’t know, here’s another hint…

Hint!

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September 11, 2001

Last hint!

Does anyone know what buildings this famous architect designed?

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Destroyed: September 11, 2001

Built: December 1971

Minoru Yamasaki is the architect famous for designing and overseeing the construction of the World Trade Center, also known as the Twin Towers!

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Scale 1 : 200

Here is a picture of the original scale model used in the construction of the twin towers.

Can you believe for years it was cooped up in a warehouse, wanted by no one. After

911, everyone wanted it! It was eventually donated to the

911

Museum

.

Look at the scale. 1:200

If it is 1 inch on the model, then it was 200 inches in real life. If it is 1 foot on the model, in real life it was 200 feet.

The height of the building on the scale model is 7 feet. In real life the height of the tower was 7 x 200 = 1,400 feet!