Scale Factor Basics
Two similar triangles have side lengths of 6 cm and 12 cm. The scale factor tells you that the triangle is 1:2,
1:4 or 1: 3
My pocket has 3 red marbles and 6 blue marbles.
What is the ratio of red marble to blue?
What is 1:2
or
what is 3:6
On a map, 1 inch = 5 miles. If two cities are 3 inches apart on the map, how far apart are they in real life?
15 miles
A blueprint shows a classroom that is 2 in by 3 in. The scale is 1 in = 5 ft. So every inch will become 5 feet. What are the real dimensions?
10 ft by 15 ft
The scale factor between two similar rectangles is 4. If the smaller has a width of 10 cm², what is the larger’s width?
40 cm
The length of a 6 inch line is reduced by a factor of one half. What happens to it?
What is, it becomes 1/2 as long.
or
What is 3 inches
Both dimensions of a rectangle are quadrupled. What is the scale being used?
What is 1: 4
A model airplane is built with a scale of 1 cm = 4 m. If the wing measures 5 cm on the model, what is the actual length?
20 m
A cafeteria is 15 cm by 9 cm on a model. If 1 cm = 5 ft, what is the width of the cafeteria?
What is 45 ft
A triangle’s sides are multiplied by a factor of 3 what happens.
Triangle is 3 by 4 by 5. So the new triangle will be?
If a square has side length 3 cm and is enlarged with a scale factor of 4, what is the new side length?
12 cm
A triangle has base 10 cm and height 12 cm. If both are scaled by a factor of 3, what is the new base?
30 cm
Janet’s room measures 16 ft long. On her blueprint drawing, the room is 4 ft: 1in. How long is her room on the blueprint.
What is 4 in
A rug is 3 m by 4 m. A similar rug is enlarged by a factor of 2. What are the new dimensions?
what is 6 m X 8 m
If one wall of your house is 20 feet long and you want to make a miniature model of your house using the scale of 5ft : 2 inches what will the length of the wall be?
what is 8 inches?
The perimeter of a triangle is 15 cm. If all sides are scaled up 1:2-- what is the new perimeter?
30 cm
A trapezoid’s area is 50 cm². If we use a scale of 1:2 or it is scaled by a factor of 2, what is its new area?
200 cm²
Sam builds a model of a 120 m tall building. His model is 60 cm tall. What is the scale?
1 cm = 2 m
A rectangle is scaled with a factor of 3. If the original area is 20 cm², what is the new area?
180 cm²
A cabin square floorplan has a scale of 1 cm = 2 m. The drawing shows 3 cm by 3 cm. What will be the area of the cabin in real life?
What is 36 m2
(new dimensions are 3m by 6m)
If a map has a scale factor of 1cm : 5 miles and they are 3 cm apart on a map-- how apart are they in real life.
What is 15 miles?
A figure’s side lengths are multiplied by 5. The perimeter increases by factor 5. By what factor does the area increase?
25
A map has a scale of 1 cm = 50 km. The distance between two towns is 6 cm on the map. What is the real distance?
300 km
A map shows South Dakota as a rectangle 20 cm by 30 cm. If the scale used is 1 cm : 6 miles what are the new dimensions
what is 120 miles by 180 miles
A building model is 30 cm tall, representing a 90 m building. What is the scale factor being used?
1 cm = 3 m
or
30 cm: 90m