Scale Factor
Definition: when you multiply the original side length by the SAME NUMBER to get the corresponding side length of the new image.
Scale factor
Carla makes a scale drawing of her garden that is 30 feet long by 24 feet wide. If the garden in her drawing is 20 inches long, how wide is the garden, in inches?
16
Justin has a model truck that is a replicate of his actual truck. The scale is 1 inch=3 feet. What is the length of the model truck if the actual is 15.6 feet?
5.2 inches
Definition: when a copy of an image is either reduced or enlarged.
Scale copy
If the original side length is 4 cm and the new side length is 24cm, what is the scale factor?
6
On a scale drawing, a helicopter is 2.3 feet long. The scale on the drawing shows a ratio of 1 foot to 10 feet. What is the actual length of the helicopter?
23 feet
A map uses a scale of 1 inch=25 miles. If the distance between two cities on the map is 7 inches, what is the actual distance between the two cities?
175 miles
Given two triangles, ABC and DEF,
AB=12 units, which corresponds to DE=4 units
BC=9 units, which corresponds to EF=3 units
AC=15 units, which corresponds to DF=5 units.
Is this a scale copy?
Yes! The scale factor is 1/3.
If the original side length is 40 units and the new side length is 20 units, what is the scale factor?
1/2 or 0.5
Pam drew a scale drawing of a game room. She used the scale 1 inch=2 feet. If the air hockey table is 5 inches in the drawing, how long is the actual table?
10 feet
Gina is traveling to the beach 20 miles away from her house. On Gina's map, the distance between her house and the beach is 4 inches. What is the scale used?
___ inch = ___ miles
True or false:
Scale copies can be stretched in and out.
False, it can only be larger or smaller in size.
If the scale factor is bigger than 1, then the image is....larger or smaller?
Larger
The scale drawing of a car length is 3 cm. If the scale is 1cm=4ft, what is the length of the actual car?
12 feet
The scale on the map is 1 inch= 2.5 miles. The distance between two streets on the map is 1.75 inches. What is the actual distance of the streets?
4 3/8 miles or 4.375 miles
True or false:
Scale copies have corresponding side lengths to the original image.
True