Scale Factor
What is the scale factor if a rectangle is enlarged from 4 cm to 12 cm?
3
A map has a scale of 1 inch = 10 miles. How far apart are two cities that are 3.5 inches apart on the map?
35 miles
What does it mean when two figures are similar?
Same size, different shape.
A model car has a scale factor of 1:24. If the model car is 6 inches long, how long is the actual car?
144 inches (12 feet)
A scale model of a house has dimensions reduced by a scale factor of 1:50. If the model door is 2 inches tall, how tall is the actual door?
100 inches (8 feet 4 inches)
A 6 ft tall person casts a 9 ft shadow. At the same time, a tree casts a 45 ft shadow. How tall is the tree?
30 feet
If a triangle with sides 5 cm, 7 cm, and 10 cm is reduced by a scale factor of 0.5, what are the new side lengths?
2.5 cm, 3.5 cm, 5 cm
How do you find the scale factor?
new/old
or
new/original
Triangle ABC is similar to Triangle DEF. If the sides of Triangle ABC are 3 cm, 4 cm, and 5 cm, and the scale factor is 2, what are the side lengths of Triangle DEF?
6 cm, 8 cm, 10 cm
A streetlight casts a shadow that is 15 ft long. A 5 ft tall person standing nearby casts a shadow that is 3 ft long. How tall is the streetlight?
25 feet.
A blueprint uses a scale of 1 inch = 3 feet. If a room measures 5 inches on the blueprint, how long is the actual room?
15 feet
A scale drawing of a garden measures 8 cm by 6 cm. If the actual garden is 16 m by 12 m, what is the scale used in the drawing?
1 cm = 2 m
A student uses a mirror on the ground to measure the height of a building. If the mirror is placed 2 ft from the student (who is 5 ft tall) and 30 ft from the building, how tall is the building?
75 feet
A house is drawn on a blueprint using a scale of 1 cm = 2 meters. If the actual house is 16 meters wide, how wide is it on the blueprint?
8 cm
A flag is enlarged by a scale factor of 2.5. If the original height was 4 inches, what is the height of the enlarged flag?
10 inches
The scale of a blueprint is 2 cm:7 feet. If the length of a room on the blueprint is 5cm and the width is 7 cm, what is the AREA of the actual room?
428.75 square feet
A flagpole and a yardstick cast shadows at the same time. If a 3 ft yardstick casts a 4 ft shadow and the flagpole casts a 20 ft shadow, how tall is the flagpole?
15 feet
A 50 ft tall building casts a shadow of 80 ft. At the same time, a nearby tree casts a shadow of 32 ft. How tall is the tree?
20 feet