Download Chapter 4.5 Isosceles and Right Triangle 2

Chapter 4.5 Isosceles and Right Triangle 2
D.I.R.T.
November 25, 2014
GIVEN: AB AD
DC BC
A
1) ∆DAC ∆______________________
by___________________
m<D=m<B why?_________________
D
B
C
GIVEN: m<DGE m<FEG
m<D m<F
D
∆DGE ∆______________________
2) by___________________
ED=GF why?_________________
G
E
F
4.5 Isosceles and Equilateral Triangles
Objective: To use and apply properties of isosceles triangles
M.2.B.
Performance Standard 3.4, 3.5 DOK­1
Knowledge MA 3
Jul 10­4:40 PM
1
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
D. I. R. T. What is an isosceles triangle?
What is an equilateral triangle?
Nov 24­10:57 AM
2
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
Objective: To use and apply properties of isosceles triangles and equilateral triangles.
Isosceles Triangle Theorem­ If 2 sides of a triangle are congruent, then the angles opposite those sides are congruent.
If 2 legs are , then 2 base angles are .
Converse Isosceles Triangle Theorem: If 2 angles of a triangle are congruent, then the 2 sides opposite those angles are congruent.
If 2 base angles are , then 2 legs are .
Feb 11­10:44 AM
3
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
What about equialateral triangles?
Nov 24­11:01 AM
4
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
Ex: Find the values of x and y.
1)
x
40
y
50 130
y
2)
x
3)
x
y
10
52 52
Nov 6­10:34 AM
5
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
4)
X
62
x
5)
2x­6
Perimeter is 18.
100
6)
x
y
7)
y
x
54
Feb 11­10:55 AM
6
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
The bisector of the vertex angle of an isosceles triangle is the perpendicular bisector of the base.
B
Find the values of x and y.
A
D
C
M
y
63
L
x
O
N
Remember????
If a triangle is equilateral, then it is equiangular. If a triangle is equianglular, then it is equilateral.
Feb 11­11:10 AM
7
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
Find the values of x and y.
y
30
x
Sep 30­3:18 PM
8
Chapter 4.5 Isosceles and Right Triangle 2
November 25, 2014
Find the values of x and y.
60
18
60
y
60
x
Assignment: Pg. 213­216 #7­10, 21­26
Draw each picture and show all work.
Nov 6­10:37 AM
9