1. STRETCHING AND SHRINKING UNIT (SS)
Investigation 1-2: Enlarging and Reducing Shapes and Similar Figures
1.2: Corresponding Sides and Angles
Learning Target: I can compare measurements in copies with different size factors.
Homework Day 2 SS 1.2: Complete p. 6 while working through the EDpuzzle.
Warm-up:
WHAT determines whether two shapes are similar?
2) WHAT is the same and what is different about
two similar figures?

2. Daphne thinks the school copier can make accurate copies in a variety of sizes.
She makes a copy of “Super Sleuth” with the size factor set at 75%.
Then, she makes a copy with a setting of 150%.

3. You will compare the three figures
You will compare the three figures. First, let’s review some important vocabulary:
Copied at 75%
Original design
Vocabulary Toolkit:
Copied at 150%
The percent (%) of the enlargement or the reduction from the original design.

4. Corresponding sides have the same relative position in similar figures.

5. Corresponding angles have the same relative position in similar figures.

6. Work with your table group to complete the table
and compare the two copies to the original on LS 1.2
Inv. 1 packet
p. 5

7. The length and perimeter of the large figure are 1.5 times (or 150%)
75% copy
The length and perimeter of the small figure are 0.75 (or 75%) times as long as the lengths of the original figure.
150% copy
The length and perimeter of the large figure are 1.5 times (or 150%)
as large as the lengths of the original figure.
How do the relationship in the angle comparisons relate to the copier size factors used?
The angle measure remain the same!

8. The area of the smallest figure is a little more than half the area of the original .
The area of the largest figure is a little more than double the area of the original.
The measures of the corresponding angles are the same, but the side lengths and the area may be different.

9. (Squares of the copier size factors!)
Each side length in the image is found by multiplying the original length by the same number.
How about the area?
Since the sides are changed by a factor, the area
(a product of the sides: l x w) is changed by a
product of the factor and itself.
(Squares of the copier size factors!)

10. Complete p. 6 while working through the EDpuzzle.
STRETCHING AND SHRINKING UNIT (SS)
Investigation 1-2: Enlarging and Reducing Shapes and Similar Figures
1.2: Corresponding Sides and Angles
Did I reach my Learning Target?
I can compare measurements in copies with different size factors.
Homework Day 2 SS 1.2:
Complete p. 6 while working through the EDpuzzle.