Download Analyzing Isosceles Triangles

The Isosceles Triangles
Theorems
Section 4-6
Isosceles Triangle Theorem
If
2 sides of a triangle are
congruent, then the angles opposite
those sides are congruent.
8
8
50
50
Proof of Theorem 4.9
Isosceles Triangle Theorem
Proof of Theorem 4.9
Isosceles Triangle Theorem
Theorem 4-10
If
2 angles of a triangle are
congruent, then the sides opposite
those angles are congruent.
Corollaries 4.3 and 4.4
A triangle is equilateral if and only if
it is equiangular.
Each angle of an equilateral triangle
measures 60 degrees.

12
60
12
60
60
12
 Parts
of an Isosceles Triangle
vertex angle
leg
base
base angles
leg
The
bisector of the vertex angle of
an isosceles triangle is perpendicular
to the base at its midpoint.
Joke Time
Who was the first
math student?
Add-em
Why
isn’t your nose 12 inches
long?
Because
then it would be a foot