Download Sections 4.5 and 4.6 - Leon County Schools

Bell Work:
1.
List 3 triangle congruence theorems
2.
If two triangles are congruent, what can
you conclude about their angles?
3.
When are two hexagons congruent? (How
many conditions must the two hexagons
satisfy?)
4.5: Isosceles and
Equilateral
Triangles
Notes
 An
Isosceles triangle is a triangle
that has two congruent sides
 The Legs of an isosceles triangle
are the two congruent sides,
and the base is the side
between them.
 The legs of an isosceles triangle
form the vertex angle between
them
 The remaining two angles are
the base angles
Partner Work
 What
are the base angles of
the large triangle?

What conclusion can you
draw about the large
triangle?
 Is
 Is
AB congruent to CB? Justify
Angle A equal to Angle
DEA? Justify
 If
I construct an Isosceles
Triangle with a line
bisecting the vertex
angle(as shown to the
right), what is true of the
two triangles formed?
 What
 What
is the value of x?
relationship do AD
and DC have?

In b., what other conclusions can we draw
about the sides or angles of the triangle?
Find m and n
4.6: Congruence in
Right Triangles(HL
Method)
Notes

A triangle is called a right triangle if there is one right angle in the
triangle

In a right triangle, the side opposite the right angle is called the
hypotenuse. The Hypotenuse is always the longest side in the
triangle

The other sides are referred to as legs
Conditions for using the HL Theorem
1.
The triangles must be right
triangles
2. Both triangles must have
congruent hypotenuses
3. Both triangles must have one
pair of congruent legs
Find x and y such that the triangles
are congruent by HL
Homework
4.5,
page 254, 256: 6-9, 14, 16,
17, 30
Honors: Add 15, 20
4.6,
page 261-263:1-7, 9, 12, 25
Honors: Add 19-22
Quiz
on Thursday!
4.5
 Find
M and N
4.6