Download Isosceles Triangle

5.2
Properties of Isosceles
Triangles
Objectives:
1. Discover a relationship
between the base angles of
an isosceles triangle.
Isosceles Triangle – at least
two sides have the same
length
equilateral triangle –
isosceles triangle with all
three sides are congruent
Parts of Isosceles Triangle:
vertex angle –
between two  sides
Parts of Isosceles Triangle:
base angles – angles
opposite  sides
Parts of Isosceles Triangle:
base – side opposite
vertex
Name each part of the
isosceles triangle below.
Name each part of the
isosceles triangle below.
Name each part of the
isosceles triangle below.
C-27
Isosceles Triangle Conj.
If a triangle is isosceles, then
base angles are congruent
_______________________.
C-28 Converse of Isosceles
Triangle Conjecture:
If a triangle has two congruent
angles, it is an isosceles
triangle.
C-29
Equilateral Triangle Conj.
An equilateral triangle is
equiangular and an
equiangular triangle is
equilateral.
Find the missing angle measures.
ma =
mb=
Find the missing angle measures.
mc =
md=
Find the missing angle measures.
me =
mf =
mg =