1. Unit 4A Geometric Figures Lesson 4 Scale Drawings
Unit 4 Geometry
Unit 4A
Geometric Figures
Lesson 4
Scale Drawings

2. Lesson 4: Scale Drawings
Objective: Swbat find the measurements on a scale drawing. Do Now: Quick Check

3. Lesson 4: Scale Drawings
Definitions
Scale models are used to represent objects that are too large or too small to be drawn or built at actual size.
Scale gives the ratio that compares the measurements of the drawing or model to the measurements of the real object.
Scale factor is a ratio written without units in simplest form.

4. Lesson 4: Scale Drawings
Stratgey: Use a proportion Scale Length Map Map Actual Actual

5. Lesson 4: Scale Drawings
Example 1: The scale on a map of Maryland is 1 cm = 24 miles. The map distance between Hagerstown and Annapolis is 4 cm. What is the actual distance?

6. Lesson 4: Scale Drawings
Try It! The scale on a map of Arkansas is 1 cm = 20 miles. The map distance between Clarksville and Little Rock is 5 cm. What is the actual distance?

7. Lesson 4: Scale Drawings
Example 2: A graphic artist is creating an advertisement of a cell phone. The scale is 5 in. = 1 in. If the cell phone is actually 4 in. in length, what is the length of the cell phone on the advertisement?

8. Lesson 4: Scale Drawings
Try It! A scooter is 3.5 feet long. Find the length on the model of the scooter if the scale is 1 in = .75 feet.

9. Lesson 4: Scale Drawings
Example 3: Find the scale factor of a model sailboat if the scale is 1 inch = 6 feet.

10. Lesson 4: Scale Drawings
Try It! What is the scale factor of a model car if the scale is 1 inch = 2 feet?

11. Lesson 4: Scale Drawings Real-World Problem
1.5 inches M
1 inch
Master Bedroom
Scale: 1 in. = 12 ft.
Find the actual area of the bedroom (sq.ft)

12. Classwork Guided Practice #1 - 4 Independent Practice # 1 - 5
Problem Solving Practice # 1 -6

13. Closure
Question: What strategy can be used to find measurements on a scale drawing?
Exit Ticket
Homework: Practice # 1 - 9

14. Exit Ticket
An engineer makes a model of a bridge using a scale of 1 in = 3 yards. The actual length of the bridge is 50 yards. What is the length of the model?

15. Homework