Vocab
Describes how we shrink or enlarge objects
Scale
A triangle has a side length of 24 inches. A similar triangle has a corresponding side length of 8 inches.
Question: What is the scale factor from the original triangle to the smaller triangle?
1/3 (8 ÷ 24 = 1/3)
A scale drawing of a playground is made using a scale factor of 1/4. In the drawing, the playground is 8 cm long.
Question: What is the actual length of the playground?
32 cm
A rectangle is 20 cm long. A drawing is made using a scale factor of 1/2.
Question: How long is the rectangle in the drawing?
10 cm
Proportion
Two RATIOS that are EQUAL
A rectangle has a length of 6 cm. A larger, similar rectangle has a length of 18 cm.
Question: What is the scale factor from the original rectangle to the larger rectangle?
3 (18 ÷ 6 = 3)
A blueprint uses a scale factor of 1/50. A wall measures 6 cm on the blueprint.
Question: What is the actual length of the wall?
300 cm (3 m)
A playground is 36 meters long. A scale drawing uses a scale factor of 1/6.
Question: How long is the playground in the drawing?
6 m
Ratio
A way to compare two numbers or MEASUREMENTS by showing how much of one there is compared to THE OTHER
A drawing of a flag is 15 cm wide. A smaller copy of the drawing is 12 cm wide.
Question: What is the scale factor from the original drawing to the smaller copy? Write your answer as a fraction in simplest form.
4/5 (12 ÷ 15 = 4/5)
A map is drawn using a scale factor of 1 cm =5 meters. Two towns are 9 cm apart on the map.
Question: What is the actual distance between the towns?
45 m
A tree is 12 meters tall. An artist draws it using a scale factor of 1/4.
Question: How tall is the tree in the drawing?
3 m
A DRAWING that shows the SAME SHAPE as the real OBJECT but at a different SIZE
Depiction
A map uses a scale factor to shrink real objects. A road that is 50 miles long is shown as 10 inches on the map.
Question: What is the scale factor from the real road to the map? Express the scale factor as a ratio (map : real).
1 : 5 (10 ÷ 50 = 1/5, or scale factor = 1/5)
A model car is built using a scale factor of 1/18 The model is 25 cm long.
Question: What is the actual length of the real car
450 cm
A building is 40 feet tall. A blueprint uses a scale factor of 1/10.
Question: How tall is the building on the blueprint?
4 feet
The NUMBER that tells you how much the OBJECT is ENLARGED or REDUCED
Scale Factor
A pentagon has sides measuring 8 cm, 10 cm, 12 cm, 14 cm, and 16 cm. A similar pentagon has corresponding sides measuring 14 cm, 17.5 cm, 21 cm, 24.5 cm, and 28 cm.
Question: What is the scale factor from the original pentagon to the new pentagon? Explain how you know your answer is correct.
7/4 or 1.75 (14 ÷ 8 = 7/4, and all other corresponding sides have the same ratio)
A scale drawing of a swimming pool uses a scale factor of 2/25. The drawing shows the pool as 16 meters long.
Question: What is the actual length of the swimming pool?
200 meters
A flagpole is 24 feet tall. A drawing uses a scale factor of 1/8.
Question: How tall is the flagpole in the drawing?
3 feet