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
If you were asked to draw a scaled copy with a scale factor of 4, the copy would be:
- Bigger
- Smaller
- Same size
Bigger
Numbers greater than 1 make the shape bigger
A rectangle has measurements 2 inches wide and 5 inches long. A scaled copy is created using a scale factor of 3. What is the area of the scaled copy?
What is 90 square inches!
Figure B is a scaled copy of Figure A.
True or False: Figure B has the same number of angles as Figure A. Explain
True. Scaled copies have corresponding parts
Mark made a box that was 8 inches long and 3 inches high.
His little brother, Dave, made a box that was 6 inches long and 2 inches high.
Dave said he made a scaled copy. Is he right?
No!
They do not have a single scale factor.
ORIGINAL AREA:
10 ft2
SCALE FACTOR:
3
SCALE COPY AREA:
?
What is 90 ft2
A scaled copy is a copy of a figure where every ______ in the original figure is multiplied by the same number.
length
Figure L is a scaled copy of Figure S.
What is the scale factor?
Scale Factor =2
A square has side lengths of 5 inches long. A scaled copy is created using a scale factor of 2.
What is the area of the scaled copy?
What is 100 square inches?
If the scale factor is between 0 and 1, then the scaled copy will be smaller in comparison to the original figure.
True!
Scale factors that are less than one make it smaller
The scale on a map is 0.5 in to 3 miles.
If the distance on the map is 3 inches, how far is that in real life?
18 miles
The scale factor is 1 in to 6 miles, so 3 x 6 = 18
ORIGINAL AREA:
8 ft2
SCALE FACTOR:
2
SCALE COPY AREA:
?
What is 32 ft2
This is the formula to calculate a scale factor.
scaled copy length divided by original length
A triangle has a side length of 36 cm.
If the scale factor is 3, what is the corresponding side length on the scaled copy?
108 cm.
A rectangle has measurements 3 inches wide and 4 inches long. A scaled copy is created using a scale factor of 4.
What is the area of the scaled copy?
What is 192 square inches?
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.
The scale on a map is 0.5 in to 3 miles.
If the distance to the beach is 12 miles in real life, how far is that on the map?
2 inches
The scale factor is 6, so 12 divided by 6 = 2.
OR multiply 3 miles by 4 to get 12 miles, then multiply 0.5 inches by 4 to get 2 inches.
ORIGINAL AREA:
9 cm
SCALE FACTOR:
?
SCALE COPY AREA:
81 cm2
What is 3
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
What is the scale factor?
Scale factor = 2
6 divided by 3 = 2
A triangle has a base measurement of 2 inches and a height of 4 inches long. A scaled copy is created using a scale factor of 5. What is the area of the scaled copy?
What is 100 square inches?
Figure B is a scaled copy of Figure A.
True or False: Figure B has angles with different measures as Figure A.
False.
Scaled copies have the same angle measurements
The scale from a postcard to painting is 2 cm to 5 inches.
If the height of the painting is 40 inches, what is the height of the postcard?
16 cm.
The scale factor is 2.5, so you can divide 40 inches by 2.5 to get back to the drawing OR
Multiply 5 inches by 8 to get 40 inches and then multiply 2 cm by 8.
ORIGINAL AREA:
1 ft2
SCALE FACTOR:
5
SCALE COPY AREA:
?
What is 25 ft2
This compares a drawing to real life.
Scale
What is the length of "Side X" if figure B is a scaled copy of figure A?
3
Scale Factor= 2
A triangle has a base measurement of 6 inches wide and 5 inches tall. A scaled copy is created using a scale factor of 2. What is the area of the scaled copy?
What is 60 square inches?
Figure B is a scaled copy of Figure A.
True or False: Figure B always has the same perimeter as Figure A.
False.
Unless the scale factor is 1, they will have different perimeters.
The scale from a postcard to painting is 2 cm to 5 inches.
If the base of the postcard is 15 cm, what is the base of the real painting?
37.5 inches.
The scale factor is 2.5. Then multiply 15 by the scale factor OR
Multiply 2 cm by 7.5 to get 15 cm, then multiply 5 inches by 7.5 to get 37.5 inches.
ORIGINAL AREA:
20 m2
SCALE FACTOR:
?
SCALE COPY AREA:
80 m2
What is 2