Definitions
To create a scale copy, we multiply all the lengths in the original figure by this same number
scale factor
All scaled copies have the same angle measure.
True
If the scale factor is greater than 1, the new drawing will be bigger or smaller?
bigger
On a city map, the scale is 1 inch = 5 miles. The distance between the library and the park on the map is 4 inches. What is the actual distance between them?
20 miles
A drawing of a flower is 5 inches tall. The actual flower is 10 inches tall. What is the scale of the drawing?
1 inch = 2 inches
A figure where every length in the original figure is multiplied by the same number and angles are all the same measure.
Scale Copy
True or False:
A Scale Factor of 1 gets you the same measurements for both the original and scale copy.
True
If the scale factor is less than 1, the new drawing will be bigger or smaller?
smaller
A graphic designer is enlarging a logo. The original logo is 3 cm wide. If they apply a scale factor of 4, what is the width of the new, enlarged logo?
12 cm
A model car is 4 inches long. The actual car is 12 feet long. What is the scale of the model?
1 inch = 3 feet
When part of a figure matches up with part of a copy. These could be points, segments, angles, or distances.
Corresponding
Polygon A is a scale copy of Polygon B.
Polygon's A longest side is 6.
Polygon's B longest side is 4.5.
What is the scale factor from A to B?
3/4 or 0.75
On a map, the scale is 1 inch : 20 miles. If the distance between two cities on the map is 3.5 inches, what is the actual distance between the cities?
70 miles
A floor plan for a house uses a scale of 0.5 inches = 1 foot. On the plan, a hallway is 7.5 inches long. What is the actual length of the hallway?
15 feet
On a map, the distance between two cities is 6 centimeters. The actual distance is 300 kilometers. What is the scale of the map?
1 cm = 50 km
You can find this by dividing the actual by a drawing measurement.
Scale
Triangle ABC has measurements of 4, 5, and 6.
Triangle DEF has measurements of 6, 7, and 9.
Are these triangles scale copies?
No
A baker is making a giant cookie replica of a regular-sized cookie. The regular cookie has a diameter of 4 inches. If the baker uses a scale factor of 5, what will be the diameter of the giant cookie?
20 inches
An architect's blueprint has a scale of 1 inch = 4 feet. The actual length of a room is 22 feet. How long is the room on the blueprint?
5.5 inches
A blueprint of a rectangular room is 8 inches long and 5 inches wide. The actual room is 24 feet long. What is the scale of the blueprint?
1 inch = 3 feet
Going from an actual measurement to a scale drawing you would _______ the scale by the actual measurement.
Divide
Triangle ABC has measurements 4, 5, and 6.
Triangle DEF has it's longest side of 9.
What is the Scale Factor from ABC to DEF?
3/2 or 1.5
A model airplane is 10 inches long. The actual airplane is 25 feet long. What is the scale of the model?
1 inch = 2.5 feet
A map of a rectangular park is drawn with a scale of 1 centimeter = 10 meters. On the map, the park is 8 cm long and 5 cm wide. What is the actual area of the park in square meters?
4000 square meters
A model of a skyscraper is 2 feet tall. The actual skyscraper is 1,200 feet tall. What is the scale of the model, expressed as a ratio of 1 to some number?
1:600