Bell Work When given the equation:

2x + 3 > x +5

Solve for x. Explain how you got your answer.

Math notebook & pencil

Scale Drawings

Scale Drawing A drawing that shows a real object

with accurate sizes except they have all been reduced or enlarged by a certain amount (called the scale).

How to Write it The scale is shown as the length in

the drawing, then a colon (":"), then the matching length on the real thing. 

Example: A drawing has a scale of "1:10", so anything drawn with the size of "1" would have a size of "10" in the real world, so a measurement of 150mm on the drawing would be 1500mm on the real horse.

Scale FactorThe ratio of any two corresponding

lengths in two similar geometric figures is called as Scale Factor.

The ratio of the length of the scale drawing to the corresponding length of the actual object is called as Scale Factor.

A scale factor is a number used as a multiplier in scaling.

A scale factor is used to scale shapes in 1, 2, or 3 dimensions.

Scale Factors

1. Size Transformation: In size transformation, the scale factor is the ratio of expressing the amount of magnification.2. Scale Drawing: In scale drawing, the scale factor is the ratio of measurement of the drawing compared to the measurement of the original figure.3. Comparing Two Similar Geometric Figures: The scale factor when comparing two similar geometric figures, is the ratio of lengths of the corresponding sides. 

ExampleFind the scale factor from the larger

rectangle to the smaller rectangle, if the two rectangles are similar.

Choices: A. 5:1 B. 5:6 C. 6:5 D. 6:7

Solution Step 1: If we multiply the length of one

side of the larger rectangle by the scale factor we get the length of the corresponding side of the smaller rectangle.Step 2: Dimension of larger rectangle × scale factor = dimension of smaller rectangleStep 3: 24 × scale factor = 20 [Substitute the values.]Step 4: Scale factor = 20/24 [Divide each side by 24.]Step 5: Scale factor =  = 5:6 [Simplify.]Therefore, scale factor from the larger rectangle to the smaller rectangle is 5:6.

Scale FactorHow do you find a scale

factor?

Virtual Nerd

ExampleTheo is on a road trip. The next gas

station on his route is 9 miles down the road. On a map with a scale of 1 inch = 3 miles, what is the distance

between the two gas stations?

ExampleLeslie made a scale drawing of

a city park. The soccer field is 14 millimeters long in the

drawing. The actual field is 98 meters long. What is the scale

of the drawing?

Example Terrence is an election officer. On election day, he travels from his home to the polling place, which appears 4 centimeters away on a map of the county. If the scale of the map is 1 centimeter = 2 kilometers, then what is the actual distance between Terrence's home and the polling place?

Dr. Noble, a marine biologist, is studying shark attacks on the coast of Lewis County. Two recent attacks took place at beaches separated by 10 inches on a map of the coastline; the beaches are 35 miles apart. What is the scale of the map?