2. Real World Application1)
882.75
107.5
11.25
wide
Width of Titanic
882.75ft w
Length of Titanic =
11.25in.
107.5in.
Width of model ship
Length of model ship

3. 1) How wide is the Titanic?
Example
1) How wide is the Titanic? w
882.75ft
11.25 in.
107.5 in. =
w  107.5 
107.5w =
107.5
107.5
107.5
w =
92.4 feet

4. Lesson Objectives 1) Use scale drawings to find actual distances.
2) Find scale factors.
3) Use scale drawings to find actual perimeters and areas.
4) Recreate scale drawings at a different scale.

5. Definition
Scale drawing - a drawing that uses a scale to make an object smaller than or larger than the real object.

6. Example
If two figures are similar, one figure is an enlargement of the other. The size-change (scale) factor tells the amount of enlargement or reduction.
If a copy machine is used to copy a drawing or picture, the copy will be similar to the original.
Original
Copy
Copy
Original
Copy
Original
Copy
Exact Copy
Exact Copy
Exact Copy
Copy machine set to 100% (scale) factor is
Copy machine set to 200% (scale) factor is
Copy machine set to 50% (scale) factor is 1 2 X 1X 2X

7. Definition
Consider Dr. Evil and Mini Me from Mike Meyers’ hit movie Austin Powers. Mini Me is supposed to be an exact replica of Dr. Evil.

8. Definition
Scale - the ratio between two sets of measurements. One of them usually is a 1.
3 in
1 in
3 in
1 in
Model(new) length
3 in =
Actual length
1 in

9. Example 2) Identify the scale factor. 72 6 36 3 1 in 6 3 1 in = = 72
The scale factor is
12 in

10. Whiteboard Practice 3) Identify the scale factor. 11.5 3 42 12 6 in 3= =
11.5
23 in 42
3.5 in
1 in
The scale factor is
3.5 in

11. Whiteboard Practice 4) Identify the scale factor. 60 10 10 1 in = 60
The scale factor is
6 in

12. Whiteboard Practice 5) Identify the scale factor. 56 1 in = 56 112 in
The scale factor is
112 in

13. Example 4 = d 52 6) 1 13 centimeters 1 Map distance 1 13 d d = =
Actual distance 13 52 52 =
1  52
13  d 4 = d 52 =
13d
The distance is 4 cm on the map. 13 13 13

14. The scale of the spaceship is 1 inch = 26 feet.
Example 7)
156 6
scale
Drawing height
6 in ÷ 6
1 in = = 6
Actual height
156ft
26 ft ÷
The scale of the spaceship is 1 inch = 26 feet.

15. Whiteboard Practice 10 = d 8) 5 1 2 kilometers
Map distance 1 2 5 5 = =
Actual distance 2 d d =
1  d
2  5 10 = d
The obstacles course is 10 km long.

16. The scale of the skateboard ramp is 1 inch = 9 inches.
Whiteboard Practice 9) 36 4
scale
Drawing height
4 in ÷ 4
1 in = = 4
Actual height
36 in
9 in ÷
The scale of the skateboard ramp is 1 inch = 9 inches.

17. The scale of the tank is 1 inch = 4.4 feet.
Whiteboard Practice
10) 22 5
scale
Model Length
5 in ÷ 5
1 in = = 5
Actual Length
22 ft
4.4 ft ÷
The scale of the tank is 1 inch = 4.4 feet.

18. Whiteboard Practice 2 = d 11) 34 1 17 centimeters 1 Map distance 1 17
Actual distance 17 34 34 =
1  34
17 d 2 = d 34 =
17d
Andrea is moving 2 cm away on the map. 17 17 17

19. The actual playground is 48 yards.
Whiteboard Practice
12) 1 8 6
actual 1
Drawing distance 1 8 6 6 = =
Actual distance 8 d d =
1  d
8  6 d = 48
The actual playground is 48 yards.

20. The scale of the whale is 1 inch = 7 feet.
Whiteboard Practice
13) 56 8
scale
Drawing height
8 in ÷ 8
1 in = = 8
Actual height
56 ft
7 in ÷
The scale of the whale is 1 inch = 7 feet.

21. Example d = 36 14) 1 2 18 actual 1 Drawing distance 2 1 18 18 = =
Actual distance 2 d d =
1  d
2  18 d = 36
36ft

22. Example d = 78 14) 1 2 39 actual 1 Drawing distance 2 1 39 39 = =
Actual distance 2 d d =
1  d
2  39
78ft d = 78
36ft

23. Example Area = L  W Area = 78ft  36ft Area = 2,808 ft2 14) Area =
Perimeter =
Area =
78ft 
36ft
78ft
78ft
Area =
2,808 ft2
36ft
36ft

24. Example 14) Area = 2,808 ft2 Perimeter = 228 ft Perimeter =
Add up all sides
36ft
36ft
Perimeter = 78 + 36 + 78 + 36
78ft
78ft
78ft
78ft
36ft
36ft
Perimeter =
228 ft

25. Whiteboard Practice d = 84 15) 1 4 21 actual 1 Drawing distance 4 1 21
Actual distance 4 d d =
1  d
4  21 d = 84
84ft

26. Whiteboard Practice d = 164 15) 1 4 41 actual 1 Drawing distance 4 1
Actual distance 4 d d =
1  d
4  41
164ft d =
164
84ft

27. Whiteboard Practice Area = L  W Area = 164ft  84ft Area = 13,776 ft2
15)
Area =
13,776 ft2
Area = L  W
Perimeter =
Area =
164ft 
84ft
164ft
164ft
Area =
13,776 ft2
84ft
84ft

28. Whiteboard Practice 15) Area = 13,776 ft2 Perimeter = 496 ft Perimeter
Add up all sides
84ft
84ft
Perimeter =
164 + 84 +
164 + 84
164ft
164ft
164ft
164ft
84ft
84ft
Perimeter =
496 ft

29. Whiteboard Practice d = 2 16) 1 2 1 actual 1 Drawing distance 2 1 1 1
Actual distance 2 d d =
1  d
2  1 d = 2
2ft

30. Whiteboard Practice d = 18 16) 1 2 9 actual 1 Drawing distance 2 1 9 9
Actual distance 2 d d =
1  d
2  9
18ft d = 18
2ft

31. Whiteboard Practice Area = L  W Area = 18ft  2ft Area = 36 ft2 16)
Perimeter =
Area =
18ft 
2ft
18ft
18ft
Area =
36 ft2
2ft
2ft

32. Whiteboard Practice 16) Area = 36 ft2 Perimeter = 40 ft Perimeter =
Add up all sides
2ft
2ft
Perimeter = 18 + 2 + 18 + 2
18ft
18ft
18ft
18ft
2ft
2ft
Perimeter =
40 ft

33. Key Points & Don’t Forget
1) Write the ratio out in words before you start the problem.
2) Scale is the new divided by the original.

34. Bibliography