Download Unit 4.1

UNIT 4: CONGRUENT TRIANGLES
4.1 – Triangles and Angles
Classifying
Triangles
Definition of a
Triangle
Classifying Triangles
by Sides
Equilateral Triangle
MA30: GEOMETRY
(Text Ref: Ch 4.1 Pg 194-201)
I. Classifying Triangles
A. Definition of a Triangle –
B. Classifying Triangles by Sides
1) Equilateral Triangle –
2) Isosceles Triangle –
Isosceles Triangle
Scalene Triangle
Classifying Triangles
by Angles
Acute Triangle
3) Scalene Triangle –
C. Classifying Triangles by Angles
1) Acute Triangle –
2) Equiangular Triangle –
Equiangular Triangle
Right Triangle
Obtuse Tirangle
Classify Triangles
Example #1
3) Right Triangle –
4) Obtuse Triangle –
D. Classify the Triangle by Sides and Angles
(1)
Labeling Parts
of a Triangle
(2)
E. Labeling Parts of a Triangle
Vertex –
Adjacent Sides –
Opposite Sides –
(3)
(4)
4.1 – Triangles and Angles (continued)
Parts of a
Right Triangle
F. Right Triangles
Legs –
Hypotenuse –
Parts of an
Isosceles Triangle
G. Isosceles Triangles
Legs –
Base –
Using Angle Measures of
Triangles
III. Using Angle Measures of Triangles
A. Vocabulary
Interior Angles –
Interior Angles
Exterior Angles
Exterior Angles –
Theorem 4.1
B Theorem 4.1 – Triangle Sum Theorem
The sum of the interior angles of a triangle is ____________.
Theorem 4.2
C. Theorem 4.2 – Exterior Angle Theorem
The measure of an exterior angle of a triangle is equal to…
Corollary to the Triangle
Sum Theorem
D. Corollary to the Triangle Sum Theorem
The acute angles of a right triangle are _______________.
IV. Find the Value of the Variable
(1)
(2)
(3)
(4)