7th grade unit 1 review

Scale Factor

100

What is a scale drawing?

A drawing that shows a real object with accurate sizes reduced or enlarged by a certain amount

200

The scale of this basketball court is 1 cm to 2m. The length of the drawing is 13.2 cm. What is the actual length of the court? 

13.2cm x 2 = 26.4 m

300

What is the height of the Eiffel Tower?

300 M

400

What is the approximate distance from Ahmadabad to Calcutta?

100,000 Miles

500

A local park is in the shape of a square. A map of the local park is made with the scale 1 inch to 200 feet. 

If a straight path in the park is 900 feet long, how long would this path be on a map?

900/ 200 = 4.5 inches

Scale Copy

100

What is the scale factor?

1

200

What is the scale factor?

6/4=1.5

300

The scale factor from ABC to DEF is 3. 

Angle ABC has an angle of 20 degrees. 

What is the angle measure of the corresponding angle?

20 degrees.

The angle size does not change regardless of the scale factor. 

400

The scale factor from ABC to DEF is 3. What is the scale factor from DEF to ABC?

1/3

500

Here is a polygon on a grid. You need to find a scaled copy of this polygon that has a perimeter of 48 units. What is the scale factor? 

Step 1: Find the perimeter of the shape below.

Step 2: How do you get from the perimeter of the original shape below to a perimeter of   48 units. 

3

Corresponding

100

What is the corresponding side of side AC?

Side DF

200

What's the corresponding angle for angle ABC?

Angle DEF

300

What is the corresponding angle to angle ACB?

Angle XZY

400

Angle ABC is 60 degrees. This angle must also be 60 degrees. 

Angle DEF

500

Triangle DEF is a scale copy of triangle ABC with a scale factor of 2.5. Segment AB has a measurement of 6 inches. This is the measurement of segment DE.

15 

Multiplication

100

5 x 8

40

200

7 X 3

21

300

62 x 1/2

31

400

A right triangle has an area of 25 square units. If you draw scaled copy of this triangle using a scale factor of 2, what will the area of the scaled copy be? 

Remember to find the area of a triangle you need to use the formula 1/2 x Base x Width

Step 1: Find the sides of the triangle. 

1/2 X______ X ______ =  25

Step 2: Once you find the sides of the triangle multiply the base times the hight

Step 3 then multiply that number by the scaled copy

100

500

A right triangle has an area of 45 square units. If you draw scaled copy of this triangle using a scale factor of 2, what will the area of the scaled copy be? 

Remember to find the area of a triangle you need to use the formula 1/2 x Base x Width

Step 1: Find the sides of the triangle. 1/2 X______ X ______ = 45

Step 2: Once you find the sides of the triangle multiply the base times the hight

Step 3 then multiply that number by the scaled copy

180

1/2 X b X h= 45

b X h= 45 / 1/2

bxh= 90

90X scale factor (2)

Area = 180

Division

100

15/5

3

200

14/10

1.4

300

645/(1/2)

1290

400

An image of a book shown on a website is 2.5 inches wide and 6 inches tall on a computer monitor. The actual book is 25 inches wide. How tall is the actual book?

Step 1: How do you get from 2.5 inches to 25 inches?

Step 2: Multiply that number by 6 inches.

60 inches

500

Sean has two different maps of NY.

• The scale on the first map is 1 cm to 10 km. The distance from Bronx to Brooklyn is 60 cm.

• The scale on the second map is 1 cm to 40 km.

What is the distance from Bronx to Brooklyn on the second map?

Step 1: How far away is Bronx to Brooklyn in km?

Step 2: Use that distance to find the distance on the 1cm to 40 km scale. 

60 x 10= 600

600/40 = 15

Answer= 15 cm