1. Do Now:
• Does the diagram given enough information to show that the
triangles are congruent? If so, state the postulate or theorem
you would use
1. 2.
3. 4.
A B
D C
R S
T
XY
Z
M L
N
K
JI
E
B
A
D
F
C

2. 5.4 Hypotenuse-Leg Congruence Theorem: HL
• Hypotenuse-Leg Congruence Theorem (HL)
– If the hypotenuse and a leg of a right triangle are
congruent to the hypotenuse and the leg of a
second right triangle, then the two triangles are
congruent.
– If ABC and DEF are right triangles, and
AC = DF, and
BC = EF, then
ABC = DEF
~
~
~
A
B C
D
E F

3. Determine When to Use HL
• Is it possible to show that the two triangles are
congruent using the HL Congruence Theorem?
Explain your reasoning.
• The two triangles are right triangles. You know that
JH = JH (Hypotenuse). You know that JG = HK
(Leg). So, you can use the HL Congruence theorem
to prove that
JGH = HKJ.
G H
J K
~
~ ~

4. Triangle Congruence Postulates
and Theorems
1. SSS (Side-Side-Side)
2. SAS (Side-Angle-Side)
3. ASA (Angle-Side-Angle)
4. AAS (Angle-Angle-Side)
5. HL (Hypotenuse-Leg)

5. More Practice!!!!
• http://www.mathwarehouse.com/geometry/con

6. More Practice!!!!
• http://www.mathwarehouse.com/geometry/con