4.7 HL Theorem
Warmup:
Draw the triangle then label the hypotenuse and legs for the
following triangle.
A
leg
hyp
Learning Target:
M
I can compare triangles using HL Theorem to
prove triangles are congruent. (G.CO.7)
Y
leg
Another way to prove Δs ≅
Is it possible to prove the given ∆s congruent by HL? Explain.
Hypotenuse-Leg Theorem (HL)
State that the triangles are right triangles then that the
hypotenuse and one leg of one ∆ are ≅ to the corresponding parts
2.
3.
for the other right triangle.
C
B
A
D
E
F
For the above triangles, which parts of the triangles might
you show are congruent in order to use HL?
Turn and talk:
Q: What are the 5 ways to prove ∆s are congruent?
A:
1.
Is there enough information to prove the triangles congruent?
Is so, which method for proving triangles congruent would you use?
4.
2.
3.
4.
5.
5.
8. Complete the proof:
Is there enough information to prove the triangles congruent?
Given: ∠ACB and ∠ACD are right angles
If so, which method for proving triangles congruent would you use?
AB ≅ AD
6.
Prove: ∆ABC ≅ ∆ADC
7.
9. Complete the proof:
M
Assignment:
Given: ∠MNL and ∠LNK are right angles
N is the midpoint of MK
N
Prove: ∆MNL ≅ ∆KNL
K
L
4.7 worksheet