See Problem 4.
-
Proof Given:
A
B
¯
║
D
C
¯
,
∠
B
≅
∠
D
,
eh b bar , box drawings double vertical . d c bar , comma . angle b approximately equal to angle d comma
A
B
¯
≅
D
C
¯
,
B
C
¯
≅
A
D
¯
eh b bar , approximately equal to . d c bar , comma . b c bar , approximately equal to . eh d bar
Prove:
Δ
A
B
C
≅
Δ
C
D
A
cap delta eh b c approximately equal to cap delta c d eh
B Apply
- If
Δ
D
E
F
≅
Δ
L
M
N
,
cap delta d e f approximately equal to cap delta l m n comma which of the following must be a correct congruence statement?
-
D
E
¯
≅
L
N
¯
d e bar , approximately equal to . l n bar
-
F
E
¯
≅
N
L
¯
f e bar , approximately equal to . n l bar
-
∠
N
≅
∠
F
angle n approximately equal to , angle f
-
∠
M
≅
∠
F
angle m approximately equal to , angle f
-
Reasoning Randall says he can use the information in the figure to prove
Δ
B
C
D
≅
Δ
D
A
B
.
cap delta b c d approximately equal to cap delta d eh b . Is he correct? Explain.
Algebra
Δ
A
B
C
≅
Δ
D
E
F
.
cap delta eh b c approximately equal to cap delta d e f . Find the measures of the given angles or the lengths of the given sides.
-
m
∠
A
=
x
+
10
,
m
∠
D
=
2
x
m angle , eh equals . x plus 10 comma . m angle . d equals 2 x
-
m
∠
B
=
3
y
,
m
∠
E
=
6
y
−
12
m angle . b equals 3 , y comma m angle , e equals 6 y , minus 12
-
B
C
=
3
z
+
2
,
E
F
=
z
+
6
b c equals , 3 z plus 2 , comma e f equals , z plus 6
-
A
C
=
7
a
+
5
,
D
F
=
5
a
+
9
eh c equals , 7 eh plus 5 , comma d f equals , 5 eh plus 9
-
Think About a Plan
Δ
A
B
C
≅
Δ
D
B
E
.
cap delta eh b c approximately equal to cap delta d b e . Find the value of x.
- What does it mean for two triangles to be congruent?
- Which angle measures do you already know?
- How can you find the missing angle measure in a triangle?
Algebra Find the values of the variables.
-
Δ
A
B
C
≅
Δ
K
L
M
cap delta eh b c approximately equal to cap delta k l m
-
Δ
A
C
D
≅
Δ
A
C
B
cap delta eh c d approximately equal to cap delta eh c b
-
Complete in two different ways:
Δ
J
L
M
≅
cap delta j l m approximately equal to __?__.
-
Open-Ended Write a congruence statement for two triangles. List the congruent sides and angles.
-
Proof Given:
A
B
¯
⊥
A
D
¯
,
B
C
¯
⊥
C
D
¯
,
A
B
¯
≅
C
D
¯
,
A
D
¯
≅
C
B
¯
,
A
B
¯
‖
C
D
¯
eh b bar , up tack , eh d bar , comma , b c bar , up tack , c d bar , comma , eh b bar , approximately equal to , c d bar , comma , eh d bar , approximately equal to , c b bar , comma , eh b bar . double vertical bar , c d bar
Prove:
Δ
A
B
D
≅
Δ
C
D
B
cap delta eh b d approximately equal to cap delta c d b