3c: Justify congruency and
symmetry of two figures (DOK 2)
4d: Solve problems involving scale
factors using ratios and proportions
(DOK 2)
By: Deia Sanders
Study these pictures
Similar or Congruent?
Vocabulary
Similar: two polygons are similar if the
corresponding sides are in the same
proportion; if the polygons are similar,
the corresponding angles will be equal.
Let’s look at pages 138 and 139
Homework
Handout #1
Pages 155-157
Day 2
3c: Justify congruency and
symmetry of two figures (DOK 2)
4d: Solve problems involving
scale factors using ratios and
proportions (DOK 2)
Let’s Review from yesterday
Please exchange papers to check
homework
Find Missing Lengths Using
Proportions
Turn to pages 140-141
Examples
Homework
Complete Handout #2 pages
159-160
Day 3
3c: Justify congruency and
symmetry of two figures (DOK 2)
4d: Solve problems involving
scale factors using ratios and
proportions (DOK 2)
Let’s Review from yesterday
Please exchange papers to check
homework for a grade
Vocabulary
Line of symmetry: a line is a line of
symmetry for a figure if the reflection of every
point on that figure with respect to the line is
also a point of the figure
(Where you can fold and object and it’s the
exact same on both sides)
Turn to page 142
Examples
Homework
Handout #3
Page 162
Closure
Where could we fold you to
find your line of symmetry?
Day 4
3c: Justify congruency and
symmetry of two figures (DOK 2)
4d: Solve problems involving
scale factors using ratios and
proportions (DOK 2)
Vocabulary
Congruent: if two polygons are congruent,
then their corresponding or matching sides
and angles are also congruent. Congruent
figures are also similar, so the
corresponding sides can also be found
using ratios.
Congruent = Same
Turn to the bottom of
page 142 and page 143
Secret trick
The sides and angles of polygons are listed
the same order, or order of congruence.
You can line up the letters from each
figure on top of each other and it will
match up the congruent sides and angles.
Examples
Homework
Handout #4
Page 164