Download Types of Triangles

Types of Triangle
Chapter 3.6
Objective- name the various types of
triangles and their parts.
Triangles by sides:
Scalene- a scalene triangle is triangle in
which no two sides are congruent
W
D
A
Isosceles-an isosceles triangle is a triangle in
which at least 2 sides are congruent
G
U
M
Equilateral- an equilateral triangle is a
triangle in which all sides are
congruent Y
U
M
Triangles by angles:
Acute: An acute triangle is a triangle in which
all angles are acute and add up to
180 degrees.
D
80
R
60
40
E
Right: A right triangle is a triangle in which
one of the angles is a right angle.
H
T
O
Obtuse: An obtuse triangle is a triangle in
which ONE of the angles is an obtuse
angle.
F
30
110
N
40
I
D
Given:
AD and CD are legs of isosceles
B is the midpoint of AC
ADC.
Prove:  A   C
A
C
B
1. AD and CD are legs of
isosceles ADC.
2. AD  CD
3. B is midpt. of AC
4. AB  BC
5. Draw DB
6. DB  DB
7.
DAB 
DCB
8.  A   C
1. Given
2. An isos. triangle is a triangle in
which at least 2 sides are .
3. Given
4. A mdpt. divides a seg into 2 
segs.
5. 2 points determine a line.
6. Reflexive Property
7. SSS
8. CPCTC
Given:
AB = x + 3
AC = 3x + 2
BC = 2x + 3
Perimeter of
A
Show that
B
ABC = 20
ABC is scalene.
C
Perimeter = 20 = x + 3 + 3x + 2 + 2x + 3
20 = 6x + 8
12 = 6x
2=x
AB = 2 + 3 = 5
AC = 3(2) + 2 = 8
BC = 2(2) + 3 = 7
ABC is scalene
because no sides
are .