Identifying Angles
Classifying Triangles
Angle Sum Theorem
Triangle Inequality
Angle Pairs
100
The name of this angle (3 possible answers).
What is:
-∠NML
-∠LMN
-∠M
100
A triangle with 3 equal sides and angles.
What is an equilateral triangle?
100
The sum of all the interior angles of a triangle.
What is 180o?
100
State the triangle inequality theorem.
What is "the sum of any two sides of a triangle must be greater than the third side"?
100
Identify the angle pair relationship.
What is complementary?
Work: 59 + 31 = 90
200
Identify the angle and determine its measurement.
What is a right angle which is 90o?
200
Classify the triangle by its angles.
What is an acute triangle?
200
Determine the missing angle.
What is 71o?
Work:
82 + 27 + x = 180
109 + x = 180
x = 180 - 109
x = 71
200
Determine if a triangle can be drawn with the sides 11, 12, and 17.
What is yes?
Work:
11 + 12 > 17
11 + 17 > 12
12 + 17 > 11
200
Identify the angle pair relationship.
What is supplementary?
Work: 146 + 34 = 180o
300
Identify the kind of angle.
What is an obtuse angle?
300
Classify the triangle by its sides.
What is an isosceles triangle?
300
Determine the missing angle.
What is 49o?
Work:
90 + 41 + x = 180
131 + x = 180
x = 180 - 131
x = 49
300
Determine if a triangle can be drawn with the sides 4, 8, and 15.
What is no?
Work:
4 + 8 < 15
300
Identify the angle pair relationship and solve for x.
What is complementary, x = 53o
Work:
x + 37 = 90
x = 90 - 37
x = 53
400
The measure of an acute angle.
What is less than 90o?
400
Classify the triangle by its sides and angles.
What is scalene, obtuse triangle?
400
Use the angle sum rule to determine the value of x.
What is x = 12o?
Work:
90 + 2x + 1 +5x + 5 = 180
96 + 7x = 180
7x = 84
x = 12
400
The missing side (x) must be at between ___ and ___ .
What is between 3 and 10?
Work: 3 + 8 = 11, but if x is bigger than 10 it will become the longest side .
(and the inequality wont work)
400
Identify the angle pair relationship and solve for x.
What is vertical angles, x = 49
Work:
126 = x + 77
126-77 = x
49 = x
500
Identify the angle that doesn't belong.
26o
84o
13o
92o
What is the 92o angle?
Work: the rest of the angles are acute (less than 90o)!
500
Classify triangle ABC by its sides, and identify the missing angle measure.
What is isosceles, x = 40?
Work: Isosceles angles have to sides of the same measure, and two angles of the same measure. So x must be the same as the other angle, which is 40o.
500
Use the angle sum rule to determine the value of x.
What is x = 14?
Work:
7x - 11 + 2x - 3 + 5x - 2 = 180
14x - 16 = 180
14x = 196
x = 14
500
Identify which set of numbers could NOT make a triangle.
(a)6,8,11
(b)9,12,19
(c)7,11,18
(d)5,6,7
What is (c)?
Work: 7 + 11 = 18
This is not greater than the other side (18) so these numbers cannot form a triangle
500
Identify the angle pair relationship and find the measure of q.
What is supplementary, q = 22
Work:
(7q−46) + (3q+6) = 180
10q − 40 = 180
10q = 180 + 40
10q = 220
q = 22