proportional.sides.similarity.notebook
January 09, 2017
Learning Objective: I can work with proportions in triangles.
Agenda:
> Do NOW!!! > Homework ?s HW: p 289 #4, 5, 6, 17 p294 #3, 6, 15, 16 > Notes & Examples­ proportional sides > Homework Reminders:
> Quiz Tues 1.10 > Benchmark 1.19 & 1.20 > Practice Test Mon 1.23 > Test Wednesday 2.2
Do Now:
1) What three theorems can we use to prove two triangles are similar?
2) What transformations can we use to prove two triangles are similar?
A'
3) Given: AB = BC = AC = 1
B
B'
A'B' = B'C = A'C = 2
Is ABC similar to A''B''C'' ?
A
C
Explain Why?
1
proportional.sides.similarity.notebook
January 09, 2017
HW: p 289 #4, 5, 6, 17 18
HW: p294 #3, 6, 15, 16 No, corresponding sides not
proportional.
2
proportional.sides.similarity.notebook
January 09, 2017
If AB ∥ DE, is ∆ABC ~ ∆DEC ?
C
C
A
B
E
D
Proportional Sides C
C
B
A
D
E
3
proportional.sides.similarity.notebook
January 09, 2017
Solve for x in each of the following. The base of
the small triangle is parallel to the base of the
larger triangle.
Pull
Midsegment Theorem
The mid
the base
4
proportional.sides.similarity.notebook
January 09, 2017
If
then 1) 18
1) Find DF
2) Find PQ
2) 30
5
proportional.sides.similarity.notebook
January 09, 2017
3)5
3) Solve for x.
4)12
4) Solve for x.
What about this???
7.5
7
HINT: Proportions :)
x+1
3
8
2
6
proportional.sides.similarity.notebook
January 09, 2017
http://mathbitsnotebook.com/Geometry/Similarity/SMSideSplitterPractice.html
Reminders:
> Quiz Tues 1.10 > Benchmark 1.19 & 1.20 > Practice Test Mon 1.23 > Test Wednesday 2.2
Homework: study!
7
proportional.sides.similarity.notebook
January 09, 2017
Given: ∆ABC is isosceles with base BC
∆DBE is isosceles with base BE
A
Prove:∆ABC ~ ∆DBE
D
B
E
C
Determine whether each pair of triangles is similar. Explain how you determined similarity.
J
6
5
K
N
4
12
10
L
12
M
8
proportional.sides.similarity.notebook
January 09, 2017
Using triangle similarity theorems. Solve for x and y.
Determine whether each pair of triangles is similar. Explain how you determined similarity.
9
proportional.sides.similarity.notebook
January 09, 2017
Determine whether each pair of triangles is similar. Explain how you determined similarity.
A
3
D
6
B
4
E 2
C
Using triangle similarity theorems. Solve for x and y.
10