Classify the Angle
Types of Triangles
Find Angle Measures
Exterior Angle Problems
Will it Make a Triangle?
100
Angles that are less than 90 degrees
Acute angles
100
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
3, 4, 5
32 + 42 ? 52
9 + 16 ? 25
25 = 25
So, RIGHT
100
The little box in the corner of a triangle or any figure represents what?
right angle
100
The Exterior Angle Theorem states that the exterior angle is equal to what?
The sum of the two opposite interior angles.
100
8, 4, 3
NO
4 + 3 is not greater than 8
200
Angles that are equal to 180 degrees
straight angles
OR
a straight line
200
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
2, 8, 9
22 + 82 ? 92
4 + 64 ? 81
68 < 81
So, OBTUSE
200
What is the measure of the interior angles of an equilateral triangle?
60 degrees
200
Find the exterior angle when the two opposite interior angles are 64 and 45.
109 degrees
200
9, 2, 8
YES
2 + 8 is greater than 9
300
Angles that are equal to 90 degrees
right angles
300
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
5, 10, 11
52 + 102 ? 112
25 + 100 ? 121
25 > 121
So, ACUTE
300
Two interior angle measures of a triangle are 39 degrees and 55 degrees. What is the measure of the third interior angle?
86 degrees
300
Solve for x:
x = 49
300
1, 1, 2
NO
1 + 1 is not greater than 2
400
Angles that are greater than 90 degrees but less than 180 degrees
obtuse angles
400
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
9, 15, 12
92 + 122 ? 152
81 + 144 ? 225
225 = 225
So, RIGHT
400
Can a triangle have these interior angle measures: 36.9 degrees, 110.4 degrees, and 33.7 degrees
Why or why not?
No, they do not have a sum of 180 degrees.
400
Solve for x:
x = 12
400
10, 11, 2
YES
10 + 2 is greater than 11
500
The number of degrees in a triangle
180 degrees
500
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
13, 9, 7
72 + 92 ? 132
49 + 81 ? 169
130 < 169
So, OBTUSE
500
Find the measure of angle Y
62 degrees
500
What is the measurement of angle B? 
angle B = 39o
500
The sum of the two shorter side lengths are greater than the longest side length
YES, it will make a triangle
600
What is the name for pairs of opposite angles formed by two intersecting lines?
vertical angles
600
What kind of triangle will these side lengths make?
(Acute, Obtuse, or Right)
8, 10, 7
72 + 82 ? 102
49 + 56 ? 100
105 > 100
So, ACUTE
600
Solve for x:
x = 12
600
Solve for x:
x = 5
600
The sum of two shorter side lengths are equal to the longest side length
NO, this will not make a triangle