CHAPTER 8 SECTION 3 NOTES
SIMILAR TRIANGLES
A. Definitions:
Two triangles are congruent if and only if _______________________________________________ so that ________________
parts (________________ and __________________) are ___________________ in measure.
Two triangles are similar if and only if ______________________________________________ so that ____________________
angles are __________________________________ and ____________________________ sides are in ___________________
TRIANGLE SIMILARITY POSTULATE: PAGE 450
***Write it in on your theorems/postulates sheet; Draw the picture***
EXAMPLES: For each pair of triangles, tell whether the triangles are similar. Write Yes or No. Explain:
E
1)
2)
B
F
D
C
A
A
50°
3)
D
50°
65°
B
70°
E
60°
65°
F
C
OVERLAPPING TRIANGLES:
∆MQR and ∆MNP are similar triangles. Name the pairs of corresponding parts
M
Q
N
R
∠𝑀 corresponds to ______
̅̅̅̅̅
𝑀𝑄 corresponds to _______
∠𝑀𝑄𝑅 corresponds to ______
̅̅̅̅
𝑄𝑅 corresponds to _______
∠𝑀𝑅𝑄 corresponds to ______
̅̅̅̅̅
𝑀𝑅 corresponds to _______
P
Explain how you know for sure that all of the angles are equal in measure.
OVERLAPPING SIMILAR TRIANGLES PAGE 452 ***Write it in on your theorems/postulates sheet; Draw the picture***
Corresponding sides of a similar triangle are _________________________ to each other.
1)
a) express all of the sides of ∆ABC and ∆ADE as a proportion
B
12
D
A
6
E
b) Use these proportions to find the measure of ̅̅̅̅
𝐴𝐷
C
24
̅̅̅̅
2) Find the measure of 𝐸𝐷
B
50
30
E
A
20
D
C