Download Congruent Figures - San Diego Unified School District

Date:
Topic: Congruent Figures
Warm-up
Construct a segment congruent to
Construct an angle congruent to
(6.6)
When congruent segments and congruent angles are combined to
make a shape, those shapes are called congruent figures.
Congruent figures have all congruent sides and angles.
Example:
AB @ DE BC @ EF CA  FD
If all of the corresponding sides and all of the corresponding
angles of a shape are congruent, then the shapes are congruent.
Therefore,
For two triangles to be congruent, all corresponding side lengths and
all corresponding angle measures must be congruent.
Corresponding means the same location of each side length or angle
on each triangle.
Example: Given
always use the same order when
naming corresponding parts
A  I
AB  IH
Congruence works for other shapes as well. As long as all
corresponding angles and corresponding sides are congruent,
then the shapes are congruent.
Example: JKLM≅QPON
Therefore,
≅
≅
≅
≅
≅
≅
≅
≅
You can use congruence to find missing side lengths or angle measures.
Example: Given
and angle measures.
11 cm
66
ÐG ≅ ÐJ
, find the missing side lengths
mÐG  mJ  66
78°
30 cm
36°
Use this same method to find the other
missing values:
28 cm
= 11 cm
11 cm
= 28 cm
66°
78
= 30 cm
= 78°
28 cm
30 cm
= 36°
36