Download Lesson 6-4 - Elgin Local Schools

Lesson 6-5
Congruent Polygons
Definitions
• Congruent Polygons- Polygons that
have the same size and shape.
• If two polygons are congruent, their
corresponding sides are congruent and
their corresponding angles are
F
congruent.
B
A
C
H
G
Congruent Angles -
A @ F,B @ G,C @ H
Congruent Sides -
BC @ GH, AC @ FH, AB @ FG
ABC @
FGH
Determine whether the triangles shown are congruent. If so, name the
corresponding parts and write a congruent statement.
y
l
4cm
9cm
m
6cm
6cm
9cm
x
4cm
z
n
Angles
The arcs indicate that x ≅ m,
y ≅ n and z ≅ l.
Sides
The side measures indicate
that
xy @ mn, yz @ nl,xz @ ml
Since all pairs of
corresponding angles and
sides are congruent, the
two triangles are congruent.
The congruence statement
is Dxyz @ Dmnl
In the figure, DAFH @ DQRN
13 in.
A
Q
F
40°
65°
9 in.
Find the measure of angle Q. H
N
R
According to the congruence statement, A and Q are
corresponding angles. So A ≅ Q. Since A = 40°, Q = 40°.
Find NR.
FH corresponds to NR. So FH ≅ NR. Since FH = 9
inches, NR = 9 inches.