Vocab
Scale Factor
Scale Factor Part 2
True or False
Misc.
100
To create a scaled copy, we ________all the lengths in the original figure by the same number. This number is called the scale factor.
multiply
100
What is the length of "?" if the two figures are scaled copies?
? = 12
100
If you were asked to draw a scaled copy with a scale factor of 4, the copy would be:
Bigger
Smaller
Same size
Bigger
Scale factors greater than 1 make the shape bigger
100
Figure B is a scaled copy of Figure A.
True or False: If the scale factor from figure A to figure B is 2, then the scale factor from figure B to figure A would be 1/2
True!
100
When scaling a shape, what happens to all of the angles?
They stay the same
200
Scaled copies have _____________ parts.
Corresponding
200
What is the length of "?" if the two figures are scaled copies?
? = 20
200
Figure L is a scaled copy of Figure S.
What is the scale factor?
Scale Factor =2
200
Figure B is a scaled copy of Figure A.
True or False: Figure B has the same number of edges as Figure A.
True. They are corresponding parts and are the same shape.
200
Multiplying by 1/3 is the same as dividing by...
3
300
A scaled copy is a copy of a figure where every ______ in the original figure is multiplied by the same number.
length or side
300
What is the length of "X" if the two figures are scaled copies?
X = 40
300
What is the scale factor?
The scale factor is 0.5 or 1/2
300
Scale factor determines the change in side lengths, perimeter, and area in exactly the same way.
False
Side lengths and perimeter scale linearly with the scale factor, but area scales by the square of the scale factor. So the effect is not the same for all three.
300
Dividing by 6 is the same thing as multiplying by...
1/6
400
To create a scaled copy, we multiply all the lengths in the original figure by the same number. This number is called the ______ ______.
Scale Factor
400
What is the length of "X" if the two figures are scaled copies?
X = 13
400
Figure B is a scaled copy of Figure A.
What is the scale factor?
Scale factor = 2.5 = 2 1/2 = 5/2
400
A scaled copy will be smaller than the original if the scale factor is greater than 1, larger if the scale factor is less than 1, and the same size if the scale factor is equal to 1.
False
Explanation
If the scale factor is greater than 1, the copy is actually larger, not smaller.
If the scale factor is less than 1, the copy is smaller, not larger.
If the scale factor is equal to 1, then the copy is indeed the same size.
400
A photograph measures:
Height: 4 inches
Width: 6 inches
The photograph is enlarged so that the width becomes 12 inches.
If the enlargement is a scaled copy, what will the new height be?
What scale factor is used for this enlargement?
Scale factor: 2
New height: 8 inches
500
A _________ ________ is the same shape, but a different size.
scaled copy
500
What is the length of "X" if the two figures are scaled copies?
X = 9.6 m
500
Figures A and B are scaled copies.
The scale factor from A to B is
7/9
What is the scale factor from Figure B to A?
9/7 = 1 2/7
500
If a scale factor is 3, then the area of the scaled copy will be 3 times the area of the original figure.
False
The area is multiplied by the square of the scale factor, not the scale factor itself. If the scale factor is 3, the area multiplies by 3² = 9.
500
A square has side length 10 cm. A scaled copy has scale factor 2.5. What are the perimeters and areas of each figure?
Original Square
Side length = 10 cm
Perimeter = 4 × 10 = 40 cm
Area = 10 × 10 = 100 cm²
Scaled Copy (scale factor = 2.5)
New side length = 10 × 2.5 = 25 cm
Perimeter = 4 × 25 = 100 cm
Area = 25 × 25 = 625 cm²
Final Answer
Original square: Perimeter = 40 cm, Area = 100 cm²
Scaled copy: Perimeter = 100 cm, Area = 625 cm²