line of symmetry

1
equilateral
obtuse-angled
acute-angled
scalene
Triangles
congruent
vertex
polygon
right-angled
isosceles
line of symmetry
2
A triangle...
vertexes

• is a closed figure (polygon)
• has three sides
• has three vertexes
• has three interior angles

side
angle
3
Classifying Triangles
triangle
first name middle name last name
4
Which angle is the largest?
A
C
B
5
Which angle is the largest?
A
B
C
6
Which angle is the largest?
A
C
B
7
Possible Middle Names for Triangles
obtuse-angled
right-angled
acute-angled
8
Classifying Triangles
acute-angled or obtuse-angled or right-angled
triangle
first name middle name last name
9
Equilateral Triangles

• 3 congruent sides
• 3 congruent angles
• 3 lines of symmetry

10
Isosceles Triangle

• 2 congruent sides
• 2 congruent angles
• 1 line of symmetry

11
Scalene Triangles

• 0 congruent sides
• 0 congruent angles
• 0 lines of symmetry

12
Classifying Triangles
equilateral or isosceles or scalene
acute-angled or obtuse-angled or right-angled
triangle
first name middle name last name
13
Give the first, middle and last name for the
following triangle
isosceles
Right-angled
triangle
first name middle name last name
14
Give the first, middle and last name for the
following triangle
triangle
obtuse-angled
isosceles
first name middle name last name
15
Give the first, middle and last name for the
following triangle
triangle
acute-angled
equilateral
first name middle name last name
16
Give the first, middle and last name for the
following triangle
triangle
acute-angled
scalene
first name middle name last name
17
Give the first, middle and last name for the
following triangle
triangle
Right-angled
scalene
first name middle name last name
18
End of Part 1
19
Recap Classifying Triangles
equilateral or isosceles or scalene
acute-angled or obtuse-angled or right-angled
triangle
first name middle name last name
20
Give the first, middle and last name for the
following triangle
What is the measure of lt A and lt B
A
B
first name middle name last name
21
Name The Angle
What is the measure of lt A and lt B
A
B
400
first name middle name last name
22
Name The Angle
What is the measure of lt A and lt B
A
300
B
first name middle name last name
23
Give the first, middle and last name for the
following triangle
What is the measure of lt A
A
300
first name middle name last name
24
Name The Angle
What is the measure of lt A , lt B , and lt C
A
B
C
first name middle name last name
25
What Can You Tell Me About These Figures?
26
What Can You Tell Me About This Figure?
27
What Can You Tell Me About This Figure?
28
What Can You Tell Me About This Figure?
29
What Can You Tell Me About This Figure?
30
What Can You Tell Me About This Figure?
31
Are These Figures Congruent?