Geometry
Notes
Name_________________________
Day 2 Warm Up
Find the value of x. Then find the measure of the exterior angle.
1.
2.
(2x)
(3x)
(2x + 10)
(7x - 50)
(8x)
F
In the diagram, ABC  DEF.
3. m A = _____
B
4. FD  _____
E
5. EDF  _____
80
40
A
C
D
Proving Triangles Congruent
5 ways to prove triangles congruent
E
Side-Side-Side (SSS) Congruence Postulate
B
D
A
F
C
E
Side-Angle-Side (SAS) Congruence Postulate
B
D
A
F
C
E
Angle-Angle-Side (AAS) Congruence Postulate
B
D
A
F
C
E
Angle-Side-Angle (ASA) Congruence Postulate
B
D
A
F
C
E
Hypotenuse-Leg (HL) Congruence Postulate
B
D
A
C
F
Examples
Decide whether the congruence statement is true.
1. DFG  HJK
F
J
2. ACB  CAD
P
B
9
A
C
4
7
G
H
K
S
7
3
D
3. QPT  RST
Q
T
R
D
Use the diagram to name the included angle between the given pair of sides.
F
4. JF and GF
G
5. HF and HG
6. FJ and JH
J
Can the triangles be proven congruent? If so, state what theorem or postulate would you use.
7.
8.
9.
10.
H