Download Triangle Angle Sum Theorem ppt.

Classifying Triangles
www.pleasanton.k12.ca.us/.../Powerpoints/4.1_Triangles_and_Angle.
..
Equilateral
Isosceles
Scalene
3 congruent sides
At least 2 congruent
sides
No congruent sides
Equilangular
Acute
Obtuse
3 congruent angles
3 acute angles
1 obtuse angle
Right
1 right angle
 Adjacent Sides: two sides of a triangle sharing a
common vertex
Hypotenuse: side of the triangle across from the
right angle

Legs: sides of the right triangle that form the
right angle

Base: the non-congruent sides of an isosceles
triangle

Vertex: the point where two sides of a triangle meet
Label the following on
the right triangle:
 Vertices
 Hypotenuse
 Legs
Vertex
Hypotenuse
Leg
Vertex
Vertex
Leg
Label the following on the
isosceles triangle:



Base
Congruent adjacent sides
Legs
Adjacent
side
Adjacent
Side
Leg
Leg
m<1 = m<A + m<B
Base

Interior Angles:
angles inside the
triangle
(angles A, B, and C)
2
B
1
Exterior Angles:
angles adjacent to the
interior angles
(angles 1, 2, and 3)

A
C
3

The sum of the
measures of the
interior angles of a
triangle is 180o.
B
A
<A + <B + <C = 180o
C

B
A
1
The measure of an
exterior angle of a
triangle is equal to
the sum of the
measures of two
nonadjacent
interior angles.
m<1 = m <A + m <B

The acute angles
of a right
triangle are
complementary.
B
A
m<A + m<B = 90o
www.pleasanton.k12.ca.us/.../Powerpoints/4.1_Triangles_and_Angle...