Chapter 4:
Discovering and
Proving Triangle
Properties
4.1 Triangle Sum
Conjecture
The sum of the
measures of the angles
in every triangle is 180
degrees.
4.2 Properties of Isosceles
triangles
Vertex angle: The angle between
the two congruent sides The
base angles are the other two
angles. The side between the two
base angle is called the base.
The other two sides are caused
legs.
4.3 Triangle
Inequality
conjecture
The sum of the lengths
of any two sides of a
triangle is more than the
length of the third side.
4.4 and 4.5 Are there
congruent shortcuts?
SSS
SAS
ASA
SAA
SSA
AAA
Three pairs of
congruent angles
Works
Two pair of
congruent sides
and one pair of
congruent angles.
Doesn't work
Two pair of congruent
angles and one pair of
congruent sides(nots
not between the pair of
angles)
Works
Two pair pair of
congruent angle and one
pair of congruent
sides(sides between the
pair of angles)
Works
Two pairs of congruent sides
and one pair of congruent
angles.(angles between the pair
of sides.
Works
Three pairs of
congruent sides
Works
4.6 Corresponding Parts
of Congruent triangles
If you use a congruence
shortcut, then you can
use CPCTC to show that
any of their
corresponding parts are
congruent
4.7
Flowchart
thinking
Flowchart proofs
are when you fill
in boxes for a
proof instead of
a two column
proof.
4.8 Proving
Special
Triangle
Conjectures
Vertex
angleBisector
Conjecture
In an isosceles
triangle the
bisector of the
vertex angle is
also equiangular
and equilateral.